Agree with most of your ideas, but I would also like to change mastery into something completely different and make the mongoose bite charge mechanic tied into something else. As it is now the mastery stat is kind of like old hit/expertise where if you don't have enough of it it's shitty RNG mechanic and if you have too much (with something like t19 2pc especially) it drops in value significantly.
In general I would like to have more emphasis on traps, bleeds and poisons instead of the current version where you dmg is mainly MB or Butchery and FS (depending on talents), with the traps and dots doing pitiful damage as filler attacks.