I eliminated most of the e-mail
You can opt out of the whole thing by going inactive, I think.
I got rid of many of the reminders etc by changing the permissions as Rob mentioned.
You might have to spend more time there than you want to but the controls are there.
As for using FB to connect to sites. This is never the only option, as far as I know. It is just a simpler option vs entering name, email, logon name and password. I have caved in for the simple several times but it is something that makes me a little nervous.