Ahhhhhh, you've hit the nail on the head on when Xander can try to regain control. (C'mon, you don't think the Scoobs would leave Alex deliberately helpless, do you?) Seriously, though, details will be coming on that.

And Spike...well, I'm somewhat basing his reactions off of how he and Dru interacted when Dru was ill at the beginning of S2. Only now he's got a soul to at least point him in the right direction, even if there are moments he's >>thisclose<< to strangling Alex.