I'll give some thought to the handicap idea, I haven't really examined it before. Your "closer to their handicap" idea is interesting. It kind of depends on how you look at it. For example, if you are looking at it in terms of the likelihood of a player getting out in X number of innings, I'm not sure how the 'caps you posted would work.
Take an Open/Pro playing a "D". The pro could get to 150 in one inning, more likely still in 2, and very likely in 3-4 innings, especially playing a "D". On the other hand, I'm not sure a "D" player is likely to get to 50 in even 4 innings, and probably would require significantly more than that.
I have some concerns about the chess clock idea, which has been discussed on the forum before. First off, what's the penalty for running out of time? Loss of game wouldn't work. Say the score is 95-15 going to 100. The guy with 95 runs out of time. Is it fair he should lose when the guy with 15 has been sitting in his chair the whole match? Another problem is what to do if both players have insufficient time to run out the game and one player's clock expires. Say the score is 60-50. The guy with 60 runs out of time but the guy with 50 points only has 3 minutes left on his clock. He couldn't get out no matter how fast he played. Then there is always the circus that would ensue as both players run low on time and the match turns into a speed pool event with one guy galloping back to his chair after a safety or a miss and the other guy bounding out of his chair with track shoes on, running at full speed to get to the table. This seems contrary to your idea of a proper event with codes of conduct and dress codes. The chess clock is just not the panacea that it appears at first. I've other concerns with it as well, but these are the most obvious ones. The idea of using a chess clock may have some merit but needs serious tweaking.