About xmen first class. What happened in there?

I mean is this a stand alone re imagining in the xmen franchise? If so howcome Brian Singer (the director of the first xmen movies) was producing it and allowing this whole thing? I mean when people do remakes they try not to rely too much o the people who did the initial remakes? On that light if it was supposed to be a remake howcome the actors who played characters like mistique and wolverine did cameos? Ok lets forget about the whole remake thing for a minute. Howcome Alex Summers is older than Scott Summers? On the first time Charles Xavir uses the Cerebro we see a glimpse of Cyclops. It was Scott Summers with his sunglasses playing baseball in the body of a preteen. Then all of the sudden the character that was supposed to be his younger brother (havock) turns out to be his older brother and incarcerated? Not very cued up to the comics eh? A lot of things went worng in that movie and I wonder if theres a site dedicated to the plot holes in that movie.