Mandos: "Tears unnumbered ye shall shed; and the Valar will fence Valinor against you, and shut you out, so that not even the echo of your lamentation shall pass over the mountains. On the House of Fëanor the wrath of the Valar lieth from the West unto the uttermost East, and upon all that will follow them it shall be laid also.
Manwë : almost immediately sends Eagle to help Fingon, who quite clearly should be counted as a follower of the House of Fëanor, rescue Fëanor ’s eldest son.
‘Echo of your lamentation' unheard. REALLY, MANWE? REALLY? I don't think Manwë can have got the note Mandos sent him. I'm guessing that there was probably a fairly stern followup note after that incident. It probably had to be quite carefully worded though, in the manner of one communicating with a boss who has failed to properly read his email
Ulmo: I am already outside the mountains, so I shall do my own thing. I think I shall enchant my favorite river so it is holy and protective against Morgoth. And recommend hidden city locations to Noldor who, no question, have in fact followed Fëanor. And I think I might just warn the residents of those cities of danger. And send an actual messenger when other communication does not appear to register with them.
Me: I’m not sure that everyone is taking the Doom of Mandos equally literally here.
I came across someone saying that the Doom of the Noldor was inevitable and that there could be no possible way out of it at all. And that even if the Noldor had got hold of all three Silmarils they would then, inevitably, have gone to war over them.
To me, if that were true, the whole story would lose its charm. I don't want to read about people being inevitably doomed. I want to believe that it is possible for them to win, if only.... And I can think of about 999 possible ways that the Doom of the Noldor could have worked out and if I had nothing else to do, I could happily write 999 AU fix-its...
OK, in canon it didn't work out - or not all that well for a lot of people, anyway - but I don't see the appeal of a story that is completely without any chink of hope. The idea of a story without hope seems very unTolkienien to me. It's not a proper tragedy if there is no possible escape. It's just a sausage factory. Even horror movies understand that.
I'm really not convinced with the idea that the Silmarils are the equivalent of the One Ring and that it's impossible for them to not cause dissention, either.
They are holy gems. The reason they cause trouble is because the (astonishingly ill-worded) Oath of Fëanor, and because the Silmaril of Doriath is set into the Nauglamír - a necklace stolen from a dragon's hoard by someone under a curse. It is not because Silmarils are intrinsically argument-provoking.