To tell the truth, I don't fancy the movies as much as the cartoons and comics (and fanfiction - btw, my FF.net profile has two links to the mutant characters created by me if you are curious) and the details of all the feature movies are mixed with each other for me - I have problems with distinguishing what happened in which movie. Look here: http://fans.marvel.com/go/forum/view/10 ... 5762/x-men A good site I am on, under the same nickname as here. I'm sure there are many other fans that can explain to you many things about the movies you would like to know. As for what I think of your questions:
1. I bet it is exactly as you say. Sabertooth is, after all, the embodiment of masculinity with a high testosterone level. He's very animalistic. For this guy fancying a woman seems to be strictly connected with agression.
2. I'm sure this is an important factor to consider.
3. I don't remember exactly the ending. But such are the holy martyrs of the Holy Holywood Gospel - people who sacrifice their lives for the greater good. It's expected from a positive character that they sacrifice themselves for others.
There are MANY comics on the X-Men. I, personally, don't follow any particular storyline, reading what I find, regardless what comic it is. In the movies Magneto was my compatriot, he even was calling his parents in Polish but the Magneto: Testament explains he was a German Jew, finally dispersing any doubts as for his origin the fans could have.
PlatedDrake - theer's also Wolverine and the X-Men series but there's just one season and they resigned from making more seasons, this one that exists is and will be the only one.