Things that should be changed or fixed already (because you haven't fixed it yet)

[FaileExperiment]

I think combat actions are coded in a way a cooldown is required. The solution is to reduce it to 0.1 seconds.

With regard to Mudras, I think what the OP means is that only successful Ninjitsu casts should trigger the 20s cooldown. Right now, because of the lag, it is far too common to enter incorrect Mudra combinations (or you actually do it correctly but the game interprets incorrectly), and these failures still trigger the 20s the cooldown. I happen to agree that the penalty for a failed Mudra input is too severe given FFXIV's known network latency issues.