As far as dice falling off the table it really doesn't happen. Funny thing is it usually only happens when one of the players uses a dice tray. The dice bounce out. Putting something in the middle of the table is a bit out of the question as the players at he ends would have to toss their dice about three feet into the box. This table is like 7 feet long.
I do like the idea of stating for dramatic purposes I want to see the dice rolls. And I really do like seeing when a player rolls a nag 20. The other night a player rolled 2 in a row, not a cheater, I saw the rolls and it was exciting.
My initial response to the cheating was, if that's how they have to play to have fun then let them, but now its effecting others.
As for using large dice I thought about bing everyone one. One player uses a blinking d20, but the group I'm with have their favorite d20 that they have been using probably for 5+ years.
I thought about putting dice towers at either end of the table and making it so the dice roll out into the center, ie the come out the bottom and roll out, but I'm not sure if that would work, if the dice would even roll far enough, and thus it could be a waste of an investment.
I think I may go with the dramatic purposes. Seriously I don't remember when a cheater rolled a 1. The other night one of the non cheaters saw a cheater roll 4d6 for a scorching ray the cheater rolled 7 damage so he picked the dice up and rerolled. This a mentioned to me afterwards.
