Line-by-line quoting is childish and annoying so here's my concentrated answer.
You implied that they don't need that information, but it seems that it is ok for you that Apple already has it. Otherwise you should have said something about it as well. And in Apple's case, it's becoming pretty serious since today and in the near future you will do almost everything with an AppleID.
Apple perhaps doesn't need to sell to third parties (like Facebook) because it uses the information itself for its own marketing and advertising. It's a vertical company.
Competition is good. When one party has already won spectacularly you don't have any more serious competition. When I say the music industry bowed I mean that we won't be seeing an alternative (and perhaps better) model of buying songs anytime soon.
As for the publishing industry, expect an iTunes-track system for paying books with all major publishers pretty soon. Especially if the iPad becomes the prime ereader and Amazon fails miserably. I hope they don't.
I backed up almost everything, my assertions had known facts from past history inside. You should have filled the blanks yourself.