Also resetting on new block isn't solution, because bad guy can start mining on every new bitcoin block & stop after 43% of standard time between two bitcoin blocks. Maybe not such effective as cheating against current pool accounting, but this will still works.
No, it won't. The whole idea of the pool abuse is that you get paid in two places at the same time. With jgarzik's scheme, it's either or. Either you get paid from the pool, or individually. You never get paid twice. If you start mining on every bitcoin block and stop after some time, you either get paid from the pool (pool found a block) or from yourself (you found a block). Finding a block individually guarantees pool shares reset and all you accumulated shares loss. And finding a block by the pool guarantees that you did't find this block by yourself since the switch time.
Furthermore, the difference between an acceptable optimization strategy (whether or not it gains you anything at all) and cheating, is IMHO the fact that if everyone used this 43%-strategy on the current system, it would break down (rounds wouldn't ever get finished), while in a only-shares-for-a-block system, the resulting gains would still be perfectly proportional to invested computation power (as share count would be reset after a block is found, even if everybody stopped pool mining, and people would join again).