Earlier quoted context omitted.
It is a question of semantics and word choice really - pretty sure that if they had said "Login with your Google Account" instead of "Upgrade to Google+", the reaction would not have been as negative. All that the Upgrade to Google+ does is tie your Google account to Google+ - you don't have to follow anyone, post anything or fill out any details of you profile. So they could have just called it : We are tying / conv…
In order to get a Google+ account, you have to give them a lot more information than you do to just get a normal Google account. And you have to use your real name or they'll disable you entire account - including email etc.
No, they don't. They just suspend your G+ account. GMail is unaffected.
Yes, there are stories of people getting both their G+ and GMail accounts suspended, but it was always for other reasons than not using a real name. One I recall was that a user was under 13, but hadn't entered his birthday until activating the G+ portion of his account, which triggered the GMail suspension. (Google doesn't allow under-13 users to have Google accounts since under US law there are extra requirements that Google doesn't want to deal with.)