It's a GAF thing in general really, but you're not wrong that this crowd in particular can be amongst the worst. People 'round here are quick to say "lol ur dumb" to establish themselves as alphas.
It's cool that you're giving this a go, though. Don't let others turn you off from a good thing. Maybe just watch the streams, listen to the commentary, and chime in on the discussion when you have questions.
Yes, but for PS4 only. If you preordered on PSN, it should automatically give you a download.
Retailers, you'll have to check your email depending on which one you use.