On the ending..
Miles will definitely be the main character eventually. Smart on Insomniac to go ahead and get the ball rolling. In general, Marvel is making an effort to familiarize casuals with Miles, with this game and the upcoming animated film hitting theatres in December being the prominent examples. As far as the in game universe goes, he's nowhere near ready to step into that role but I'd wager the next few sequels will likley see Peter training Miles for that day. No doubt we'll also have to play as Miles in bits and pieces, which should be fun. Pete's a good 3 to 4 games away from passing the torch, but I like Miles. His inclusion makes the incel dorks angry, so I'm all for it. I hate that they killed off his pops, though. His father being true to his comicbook character and loathing superhumans would have been a very interesting dynamic to explore.