cool theory, hansel.
i like it, that's what i think is going to happen. with millar, no scene or line is ever wasted, besides maybe "you stupid cow!" i think the first scene is indeed foreshadowing, and the fact that it is scarlet witches' purse is just more evidence: she would make quicksilver get it.
it's either that, or hawkeye's family was simply made by the scarlet witch, which she used to manipulate him to leak all the info because she is the traitor and loki's apprentice! :twisted:
but yeah, i think the avenger's idea is cool, except for the fact i think it'd be funny if all the avengers did was go around and stop family-cides from happening, or say stuff like this:
Ultron: BWAHAHAHAHAHA! THE WORLD IS MINE!
Cap: No! We will stop you, and thus avenge Hawkeye's family!
*fightscene*
Cap: We've won... the day is saved.
Hawkeye: Now... maybe then can finally rest in peace.