Ok I have very little understanding of Stick's effect(or Iron Fist for that matter), but my understanding is this. I could use it on a MK char and play for example Clobberin' Time since a char is targeted. I cannot play for example Bamf or Inside Job since a char is not targeted, correct? I would need Midnight Sons for those two, right?

You seem to be doing all right with them. Remember, though, that you don't need to control an X-Men character to play Bamf; your characters simply won't benefit from the effect unless you have an effect like Midnight Sons' giving them the X-Men team affiliation.