I think you'll be fine. The little bit of compression of the fiberglass won't hurt and it will help to keep insulation from sagging. It looks like you're doing a good job sealing the foam board.

Your plan is on the right track, and I would leave the pink foam boards in place. They help break up heat loss through the framing, and unfaced fiberglass is a good choice here because you do not want a second vapor barrier trapping moisture inside the wall. Fill each cavity fully and snugly, and split the batts around wires and pipes instead of stuffing them behind obstructions, since a little light compression is fine but a heavily bunched batt loses performance. Before you close it up, tape or caulk the foam seams and seal around outlets and any penetrations to cut down on drafts. If the wall is dry and leak-free, mold should not be a concern, and a coat of vapor-barrier primer or paint on the drywall can add a little extra protection in a cold climate like Detroit.