Without the Spirit of Fire?

[symestreem]

Aman would have been better, because the elves never would have left, and there might not have been the Kinslaying. However, if Feanor had never been born, then Serinde would not have died, Finwe would not have remarried, and Fingolfin and Finarfin would not have been born. Hence, no noble houses of the Noldor except for Finwe and his children (I'm assuming that a less fiery child than Feanor would not have killed Serinde, and they would have had other children.)
Without Feanor, Morgoth would not have been as effective in his sowing of divisions in the elves. Also, if the elves did not go to Beleriand, then men would have fallen to Morgoth. So you would have bliss in Aman for a while, but hell everywhere else. Eventually, Melkor would have gotten strong enough to challenge Aman. Who can say what would have happened?
It's kind of hard to say. Each small action that occurs causes the world to change. Have you ever heard of the butterfly theory, that if a butterfly flutters its wings over China it could cause a hurricane in Brazil? Another theory is that each of these actions causes a new world to be created, so there are trillions upon trillions of parallel universes out there. It's like a tree, always growing and branching. We can look back along our branch, but we cannot look at another branch. If you believe in clairvoyants, they can look at future branches, but they do not know which will occur. This is what Galadriel meant about the things in the Mirror not necessarily happening. So, it's hard to say. We can only guess.