Biggest Plot Holes

Not sure if this has been discussed before but having revisited this film, the ending is probably the most disappointing thing about story.

I remember seeing this in the theater with my brother and he said, "Why did Magneto need to use the Golden Gate Bridge to get the brotherhood to the island, it makes no sense." That part didn't bother me. The simple answer is that Magneto is a terrorist, although he fancies himself a freedom fighter, and terrorism is about making big political statements. So it made sense for him to do that. Here's what doesn't make sense.

-How the hell does the GG Bridge continue being a bridge when its no longer suspended by anything. It would have made more sense if the front half that landed on the island with the mutants on it was the only part of it that was still there while the rest of it collapsed into the sea.
-Why in the holy hell, if Magneto has the power to uproot and fly the GG Bridge across to the island, did he not just destroy the cure facility himself. He could have easily done it by himself without his brotherhood having to be picked off one by one. Its not as if the facility is made of plastic and even if it was, which I doubt, the original prison is not.
-Why did Magneto bother recruiting Jean if she was just going to stand there and do nothing until literally every other brotherhood mutant was defeated. Recruiting her was a major plot point and it didn't pay off at all. I did see the deleted scene where Magneto tells Jean to listen to him, it would have been better had they left it in. But it still wouldn't have saved this plot point.

Just my thoughts. I still enjoyed the movie.