Bollocks, I think you are right. I remember there being some news item that was geek-candy in the first one about the political ceremony that Magneto interrupted with his flashy-bang, but I can't remember what the geek-candy part of it was.
It seems we're both right. He was doing some sort of experiment to reduce his mutation (or the visual effects of it) and instead jump-started it, giving him the fur and whatnot.
So Leech could potentially affect him. I'll buy it.
That the saints may enjoy their beatitude and the grace of God more abundantly they are permitted to see the punishment of the damned in hell. -Saint Thomas Aquinas, Summa Theologica