The problem is that it's Merv Griffin's Crosswords meets Russian Roulette, minus the excitement or strategy of the latter, but adding the ambiguous answers of the former. A better trivia format could work...say answers have increasing number of letters AND difficulty. Right now it's just a pedestrian tennis match...back and forth, back and forth. And there's no fun in seeing the contestant pick an opponent arbitrarily because he or she doesn't like Skippy's Argyle sweater.
Just to tinker with it, assign each opponent a category, with escalating difficulties. That way, the main contestant could use some strategy in who to play first to build the bank. It's not much better, but it gets rid of the tennis match going on now. I do like the idea of the Grand Slam clock. A lot.
I'd even suggest allowing the contestant to add a letter or "buy a clue" (Get it?! That's rich!), but with a penalty
And drop the trap door concept (no pun intended), and come up with a different title.