Talk with Crush is in the Animation Station, and runs continuously throughout the day. When you get in the building go to the right, and you can ask the CM when the next show is, then wander around & enjoy the projections on the walls and displays until time to go in (or it might be time to go & wait right away).
Brother Bear is set in a little amphitheater type seating in the Redwood Challenge Trail area -- go to the left when you go in. I've never seen it very crowded, but it's been awhile since I have seen a show there.