Lots of wackiness happened today for me.
#1: I got a ball perched on top of the visor, by shooting it there just as the barrier lifted during multiball. While it was there, it continually triggered the leftmost visor target, rapidly completing that Mega Visor round for me. (Then the visor lowered the ball back into play.) This happened twice in my game.
#4: I can also confirm that Dirty Pool exists and works in the TPA version. Get a ball caught behind the visor, then shoot it to newton the ball into an eye. This also completes Mega Visor immediately.
Yeah, I've had the ball catch on the visor like that a few times. Usually it rolls left/right, while continuing to register hits on the targets. I don't think I've had it happen during Mega Visor yet. I've also gotten Dirty Pool once, though I wasn't quick enough to get a screenshot.