Not through the app but using some other service probably. I think you can make your own wallet if you have a lightning node too but I’m not totally sure how that works.
I’m not sure about the first point but I agree with the second. Nostr used to be like 99% bitcoin posts but it’s better now. I don’t really care if ppl like bitcoin but most are cultists that say ridiculous things and don’t want to have actual discussions about the problems it has.