I've got a question maybe the community already looked into, i find different sources and dont have the ability to verify anything myself at this point of time.

The question is, how does PS, CoT etc. work? Do the skills snapshot on what level they are when you build the skill up or when you actually release them with finishing strike?

Im wondering if there's any use of a +6 claw combinations on weapon swap.

The lvl of the skill is determined when the charge is released. So no, you can't prebuff it.
It would be a waste of time anyway since we're talking about the most absurdly overpowered build... there's virtually no difference between killing in 1 hit, or killing in 1 hit.

Optimize your fcr and ias breakpoints
This build got more than enough dmg already

You kill anything in 1 set of kicks even with 8 players in the game. Why would you like more damage? To kill baal in 2 seconds instead of 5? You would lose more time prebuffing.

Bigger number @ character screen = Improved gameplay ofc