Since X2 showed her getting Stryker's lab plans and breaking Magneto out of prison, I've thought Mystique being clearly the most competent spy of the lot, with her shapeshifting abilities the least of it.

re: Mystique's collaboration (or not) in X3 - I only watched it once, and many years ago, so I can only go by memory which is vague.

My problem was really with how they ended up at that point - Mystique's actions came across to me like a petulant young woman going against the two father figures in her life (okay Charles is her brother and Erik was probably her lover, but as you say, there's a distinct paternal bent to both relationships). She's told by multiple people not to do it, for good reasons, and has the chance to work alongside friends to take down the Sentinel program in other ways... and yet she perseveres.

Well, if I recall correctly neither Charles nor Erik told her what their plan for preventing the Sentinel program was. Well, Erik's plan after his plan A (killing Mystique) didn't work out and became redundant because Trask had gotten hold of her DNA already. I don't think Charles had a plan as such, given that he'd been told by Logan only that Mystique killing Trask was what triggered the whole ghastly development and if that could be prevented it wouldn't happen, so basically the two things he offered earlier was to say "don't do it" and "come home". To which, yes, she responded badly, but I don't think it was just because she didn't want to be bossed around by Charles (or Erik) anymore. If Charles had said "don't do it because we'll do such and such instead", I think she still would have probably have seethed at him but would have gone along. She really had an urgent need to do something.

Erik being in top shape after a decade of imprisonment: so much so that at first I thought they must have caught him only recently, but then the movie later had Charles and Erik mention that he really did get imprisoned that long, so I've got nothing.

Stinger explained: oooohhhhh! Okay then. Thank you for explaining.

Charles/Hank: good to know I'm not the only one who sees it here!