I think the part you're missing, Zangetsu, is that autoattack is not "the game presses buttons for me". It is an entirely separate thing from activated abilities that perform a unique function or serve a purpose.

Autoattack is just periodic swings for damage that consume no resource whatsoever. Without having some sort of depletable resource, these attacks really cannot carry added effects outside of raw damage (and yes, this extends even to things as minor as changing the damage type attribute). All the abilities you just listed will most likely not exist once auto-attack is fully functional, or if they do it will be in an entirely different capacity. You're just used to spamming them instead of the game having auto-attack.

Once autoattack is implemented, there is no reason at all for light stab and light slash to exist as they do now. They will be rendered completely obsolete.