For the stuck ball in the THOR targets you have to lift the playfield and adjust the height of the drop targets so that they are flush or slightly higher than the playfield surface. I think it's a one screw adjuster, but I'm not by a game to check. Once you have the targets "flush", there will be no cavity for the ball to get stuck into and it will roll out easier.

edit: Yeoldpinplayer pretty much mentioned this earlier btw, I just didn't read it completely

I can't say for sure because I'm not near any of my games, but essentially you would be adjusting the plate that stops the bottoms of the drop targets from dropping down into the cabinet. This "plate" needs to be pushed up slightly to make the tops of the drop targets flush with the top of the playfield. Got a pic of the mechanism?

I would tighten the top screw slightly with the targets down, while watching the top of the "T" target as it comes up level with the playfield surface. This should decrease the likelihood of the ball getting caught there.