#and i do find them at least partially culpable for the first kinslaying

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If the Valar had their way, the fleeing Noldor would never have left Aman, and it's likely that Morgoth would have destroyed/enslaved all of Beleriand (possibly excepting Doriath, but I also think it's likely that Morgoth bringing his full power to bear on the Girdle would have overwhelmed Melian's power, so, maybe not), and then continued to expand his power eastward to the rest of Middle-Earth, possibly getting the opportunity to entirely wipe out, enslave or "corrupt" the humans as well (once they were around).

Canonically the Valar didn't want to intervene in M-E because it would have been too destructive (which, if Morgoth had already destroyed everything, at least wouldn't be a concern) and because they didn't know if they could defeat him again. (JRRT's notes in HoME say that Morgoth was not only the most powerful Vala, but that he was specifically more powerful individually than the rest of the Valar collectively.) The "Morgoth's Ring" analogy suggests that, in "corrupting" a greater portion of M-E than he did in canon, Morgoth would have eventually distributed/diluted his power enough that the Valar could defeat and destroy him, but he also would have had a chance to wreak more destruction on M-E without the exiled Noldor (and the Sindar they rescued from his first siege) there to constantly combat the destructive efforts of his creatures. (It's also arguable that this combat helped weaken Morgoth more quickly than he might otherwise have diluted himself, since I think it's plausible to say that each orc, dragon, etc that died took with it a small part of Morgoth's power, and without strong direct military opposition, it would have taken far longer than 550 years for Morgoth's power to be distributed enough that his "self" was weak enough to be defeated by the Valar.)

While Fëanor's faction could have crossed the Helcaraxë rather than stealing the ships, it's difficult to say exactly what the situation in Beleriand would have been by the time they arrived and Morgoth had had 30 years to consolidate his power and to expand it. I frankly don't think even the Noldor with their preparation and weapons would have been able to effectively stand against him at that point, and even if they avoided being wiped out completely, they certainly wouldn't have been able to build fortresses anywhere in Beleriand, much less the kind of hidden strongholds that Nargothrond and Gondolin were. If the canonical Wars of the Jewels were the elves of Beleriand fighting the "long defeat", it's easy to imagine that a smaller, later, and less-resourced Noldorin host might have rather faced a "short defeat" and been quickly relegated to small pockets of resistance with less overall effect than the organized war effort they put forth in canon (which itself was not enough to fully defeat Morgoth, and would not have been capable of defeating him even if they hadn't been weakened by infighting).

So, to come back to the beginning of the post, it is the Valar's interdiction that caused Olwë and his people to refuse to charter or lend boats to the Noldor; however, I would argue that, despite the Valar's ruling, the Noldor arriving in Beleriand fairly close on Morgoth's heels was an essential part of minimizing the harm Morgoth was able to do to M-E. Obviously, this came at the cost of many Noldorin lives and, due to the kinslaying, many Telerin lives as well (plus the trauma of betrayal and violence from their fellows), but the Noldor arguably had a right to choose to go get themselves killed in Beleriand, even if the Valar disapproved and even if they path they took to get there was not something that was within their rights to do.

I don't mean to divert blame, but as I said above, the Valar's ruling led directly to Olwë's refusal to aid Fëanor, which itself precipitated the First Kinslaying. Although it doesn't justify murder (or, arguably, theft), it doesn't seem like there was any method other than stealing the ships by which any portion of the Noldor have have arrived quickly in Beleriand, especially since the Valar refused to aid the Noldor in leaving. "Freely you came and freely you shall depart" feels rather cheap when the free coming was with Valarin assistance, yet the allegedly-free departure lacks that same assistance. While they did not formally prohibit the Noldor from leaving, the Valar did actively, passively, or by proxy close off many avenues by which the Noldor might have left, leaving the fight which ended in Kinslaying as the fastest (and possibly the only fast) way to get to Beleriand.

And that speed in arriving, as I've laid out above, was essential to allow the (relatively) rapid defeat of Morgoth by the end of the First Age. So it's possible that the First Kinslaying (and subsequent Doom of the Noldor) was a necessary element of the "best possible outcome" for M-E as a whole, once Morgoth had fled Aman and the Valar had determined that they would not intervene in M-E for the foreseeable future. Which is not to justify it as a choice or action that the individual actors involved made, but rather to suggest that the Valar forced the Noldor into a situation where any choice they made would have resulted, either directly or indirectly, in some degree of preventable death and destruction, and despite the horror and fundamentally indefensible character of the First Kinslaying, that choice probably decreased the destruction wrought by Morgoth on M-E and its inhabitants significantly.

The Problem of Evil remains unsolved.