These are ridiculous ideas.
It's everyones interest to join a strong clan, the ability bonuses are the best motivation to lower level players. I dont personally think it's a good idea to remove these bonuses, just so a weak under lvl50 player could win a championship once in a lifetime with some luck. I guess we all know that these ability bonuses won't make any difference after a certain level...
This cumulative damage won't work either. It would only increase the difference between the stronger and the weaker players, if the latter start to increase their contitution and execution instead of the more useful skills.
In the last normal championship I only lost around 10% of my hp in 2 battles, so that means I could have beaten anoter 15-20 players if I don't run into someone with a level 8-10000 execution skill. I can't imagine spending that much SE on an almost totally useless skill.

The one and only Fakkjoresszvitbróköngless.
Efficiency is key.