I have ten feathers from the RAF program.

I see that I can buy a nice i110 weapon and some gear for level 50. Is there any point to buying these things, or will they be replaced so fast as I go through the story content at level 50 that it would be a waste?

Will I ever earn more of the silver feathers somehow, or only the gold ones?

Is there anything anywhere else to spend the silver feathers on, or just what I see now for level 50 and under at the Calamity Salvager?

Thanks!