Didn't they just have a professional tennis match where it went something like 54 match points in a tiebreaker?
Wimbeldon: one player won the last set in a 70-68 (no tie-breaker). The match took place over 3 days--it was called for darkness, twice.
I tend to like the idea being presented here, but I still think both the chess clock and the 20-30 seconds and then the time bank need some additional thought.
Perhaps something like:
1) A player gets 30-45 <pick one> seconds to make their first shot, with a single extension per game.
2) any time not consumed on the shot is added to the subsequent shot, and so on.
3) time carryover is terminated at the end of a rack (for games other than 14.1)
So If a player arrives at the table, and pots 3 balls in only 15 seconds, that player would have 30+25+25+25 = 105 seconds for his 4th shot, and still have the extension available.
The unfortunate thing is that this basically requires a time keeper, and a computer rather than simple clocks. The time keeper aspect could be performed by the player (probably), but still, this requires a computer (laptop) at each table.