[art by me with help from SemperViridis]
Because Fëanor is a canon character I don't really need to elaborate on his background, hobbies, etc - I assume you've either read the Silm or you're capable of reading this to find out more about his canon if you want to know - so instead I will talk about a few perspectives I have which informs how I write him.
Thing #1: Fëanor Is Autistic As Fuck
Fëanor is canonically gifted and talented [a linguist, inventor and artist], precocious, and Bad With People. If you're autistic, you're nodding your head at this/stimming/etc because you already know these are some of our "calling cards".
Fëanor married Nerdanel, who was canonically not-pretty [plain by elven standards, but not ugly per se], but she was a sculptor [fellow artist] and said to be "wise". In other words, Fëanor wasn't hung up on looks but was much more interested in her brain. This, too, is classic autistic shit.
Also, I tend to write Fëanor as a sensitive artist who just wants to hang out in his forge and make stuff and doesn't really enjoy being royal and the functions/formality/socializing/etc expected of him. Fëanor, canonically, was a smith. A smith's forge is a sooty, smoky place. You wear practical work clothes. You are not poncing around in silks and fainting at a little dirt.
Tolkien, who was Very Very Christian, wrote the Silmarillion as a morality play much moreso than his other works. LOTR sent the message that even the "smallest" of us are capable of making a difference against evil, which was great. The theme of the Silm is that "pride goeth before a fall", and - I'm gonna piss off people saying this and IDGAF - Tolkien seemed to take glee in gratuitously torturing Fëanor and his family for their "bad attitude". That was not so great. Because, look. As an ex-fundie, the "put you in your place" "breaking" is religious bullshit I am very, very familiar with. Actions have consequences, I am not disputing that. However, I feel that this was a case of "don't you dare take that tone with me" taken to extreme levels.
Even though Melkor had egregiously fucked up before, the Valar gave him a second chance, didn't keep him on a short leash and then collectively made the surprised Pikachu face when he murdered Finwë [Fëanor's father], stole the Silmarils [Fëanor's greatest creation, more on that later] and sent his girlfriend Ungoliant to go eat the Trees and plunge the world into darkness. But then they also had a problem with Fëanor calling them out on their incompetent bullshit and being angry that he was asked to relinquish the Silmarils to correct their fuckup.
My take on reading this, as an autistic person, is that a lot of us neurodivergent people who get bullied, when we defend ourselves, we are seen as the ones at fault, the ones "starting shit" - the perpetrators rather than the victims. I don't think Fëanor did anything wrong with telling Manwë to fuck off and leading his people out of Aman. But I know my opinion is a minority.
Another thing that not-infrequently happens to autistic people is that our bullies lie and make up bullshit about us. I've had this happen to me [in one particularly notable instance it was ironically, by someone who stans Fëanor], and I've seen it happen to other neurodivergent people.
On Tolkien's grave he has the name "Beren" and his wife has the name "Lúthien". In my multiverse I play with the idea that Fëanor and his brothers reincarnate as humans; in my multiverse I also play with the idea that Tolkien actually was Beren and his fiction was based on his memories [and Christopher Tolkien was Pengolodh].
This also means that in my multiverse, I play with the idea that the Silmarillion was written by an unreliable narrator, the headcanon that the human Beren was jealous of the elven Celegorm [one of Fëanor's sons], seeing him as a rival for Lúthien, and decided to smear him and his whole-ass family [except Finrod]. So, I headcanon that Fëanor/etc were attacked first by the Teleri and they defended themselves, but Beren's history spun it as Fëanor/etc gratuitously murdering the Teleri. "We told him our ships are to us what the Silmarils are to him and THEN HE ATTACKED US" straight-up sounds like some neurotypical make-up-lies-about-autistic-person shit [especially considering how fiercely he loved his sons and attacking first would recklessly endanger them].
This doesn't mean Fëanor "did nothing wrong". I could not tell you if he went too far in defending himself and his sons and his people against the Teleri. But yes, even though he was traumatized by the loss of his father and the Silmarils and a lot of people dealing with active trauma make rash judgments, that still always felt "off" to me.
As far as Finarfin's response goes, I headcanon that Fëanor told Finarfin to go back [see below].
Thing #3: About Those Ships... And My Problematic Ships
I ship Fëanor with both of his brothers [Fingolfin and Finarfin]. No, I don't condone incest IRL; I am a CSA survivor. However, as a writer there is something interesting to me about the psychological dynamics of King Shit Finwë kind of being an asshole and his sons turning to each other for comfort, as dysfunctional and fucked-up of a coping skill that may be. As a mythology geek, one of my headcanons is that one of the reasons why the Laws and Customs of the Eldar were made was because pre-Valinor, back in Cuiviénen, everyone was getting it on with everyone including siblings - and sibling incest was A Thing in the Greek pantheon, the Norse pantheon, etc - so this was one of the ways the Valar subjugated them and kept them from attaining apotheosis, if there was a hard limit on who they could do the sex magic stuff with. [January 2024 note: this is fiction, I am converting to Judaism which is monotheistic.]
And as an enthusiast of the male form, there aren't a lot of people in the Silm who aren't related to each other, so it's hot guys with available hot guys.
SO ANYWAY, one of my headcanons about the incident where Fëanor pulled a sword on Fingolfin in public and threatened him was that it was either 1. Fëanor and Fingolfin were lovers in private and this was against the Laws [not just the incest, but also the gay, since the Laws were compulsory cisheteronormativity (and if you're coming here to argue that LACE was totally queer-friendly, please don't)], so they had to pretend to be enemies to avoid suspicion and punishment** - like I wrote in this fic here, 2. major UST if they hadn't gone there yet [which I will eventually write somewhere].
**By extension, Fëanor had to pretend to disapprove of Fingon hanging around with Maedhros, but I also headcanon that he was totally fine and supportive of their relationship, until the end when he snapped.
Fëanor burning ships so Fingolfin and his host [including Fingolfin's son Fingon] couldn't follow him into Middle-Earth read to me more like the actions of a scorned lover than mere sibling rivalry. I headcanon that Fingolfin rejected Fëanor after their father was murdered, feeling they were "cursed", and that was Fëanor's trauma-addled response.
So this is why I'm not on Team Fëanor Did Nothing Wrong. While I headcanon that the First Kinslaying didn't happen the way canon said it did, and I don't blame Fëanor at all for telling his people's gods to go fuck themselves and noping out of Aman, I do absolutely think that Fëanor was wrong to burn the ships. It was an understandable-if-you-understand-trauma wrong, but it was still wrong.
And in universes I've written where he's re-embodied [like Keep You Like An Oath, the sequel to Shades Of Silver-Gold] or when he reincarnates as human and Sören begins to have past-life dreams/memories, there is an acknowledgment that yeah, this is where he fucked up. People died when they had to cross the Helcaraxë on foot, and this is something that re-embodied or reincarnated Fëanor has to live with.
About Finarfin: I headcanon that Fëanor told him to go back to Aman, either because Fëanor was trying to protect him from the Doom, or Fëanor was having a "push everyone away" response. [And yes, Finarfin canonically lives, but in my multiverse Finarfin usually dies in the War of Wrath and reincarnates as Anthony.]
This is a fic I wrote in my Omegaverse Silm AU about what happened. [There is no pregnancy in that one particular fic, but there is a heat.]
For flavor: across my multiverse I either write Fëanor as bi [where it was genuine with Nerdanel but he also had a thing with his brothers and maybe some other dudes], or that Nerdanel was his "beard" or he was coerced into marrying her.
...Also I write Fëanor as a bottom, I'm just sayin'. [Other people almost always write Fëanor as a top in slash fic, and I feel like a lot of cis women do this thing in slash fandom with "the older/bigger one always tops" and no offense but speaking as a queer man, this is annoying as fuck and also problematically gender essentialist but nobody asked me -sips tea-. I realize that discussing how "realistic" sex is in a fantasy setting with non-humans is kind of ridiculous, and in any case I practice KINKTOMATO and I don't leave people mean comments on AO3, but on my own journal yes, I have the right to talk about pet peeves and this is one.]
Thing #4: The Silmarils Were Not Just Some Shiny Rocks
In meta/memes about the Silmarillion, you will often hear that the Noldor [Fëanor's people] and the Fëanorions [his sons] specifically did horrible things over "a bunch of rocks".
So, to back up a bit, in Tolkien's mythos, there were two magic trees, Laurelin which gave golden light during the daytime, and Telperion which gave silver light at night. Fëanor was kind of obsessed with the Treelight [another autistic "calling card" of hyperfixation and "ooh shiny"], and this inspired the Silmarils.
After Ungoliant went OM NOM NOM on the Trees and the world was plunged into darkness, the Valar asked Fëanor to give up the Silmarils to replace the Trees, and he would not.
People who hate Fëanor typically bring this up to show off "what a selfish asshole he was". Once again, I am reading this as an autistic person - he shouldn't have had to break his magnum opus to correct something that was ultimately the fault of the Valar [they shouldn't have trusted Melkor], especially when the Valar, as gods, were more than capable of creating something to replace the Treelight themselves and they did - in Tolkien's mythos this is when the Sun and Moon were created.
That they went to him first instead of just, you know, going ahead and making the damn Sun and the Moon, tells you right then and there that these were more than "shiny rocks". There was power in these stones. A lot of fucking power.
It was that level of power that Melkor craved, and that was why Melkor stole them. It wasn't that they were pretty. If he just coveted shiny things, he could have hired someone or made them himself. He knew what they were.
The Valar had already fucked up once, and Fëanor didn't trust them with that kind of power, and in my opinion rightfully so.
It was that power, that holy fire, that Fëanor's sons took an Oath to reclaim, to fight for, to kill for if necessary, to die for, because they understood this power could not fall into the wrong hands - like Melkor.
[And while I simp for Maglor in the worst way, I am also not here to defend his and his brothers' actions in upholding the Oath to you - one can have good motivations and still fuck up, this is not mutually exclusive. I don't particularly enjoy the "Maglor goes back and repents to the Valar" fix-it fics and I don't write those, I do tend to write a contrite Maglor who won't "go home" and kiss the Valar's asses but still spends his days in Middle-Earth trying to be kind and helpful to others.]
And also, I headcanon that Fëanor made the Silmarils in honor of his brothers [one for each of them, and Fëanor himself] and it was his way of publicly acknowledging his secret love for them, a tangible reminder of the love and warmth they shared. Love is one of the most powerful forces in the world, and passionate, fiery, all-consuming love from the Spirit of Fire himself empowered those stones.
And that's about all I have to say right now. If I find myself having more to share, I will make a Part Two.