We seem to have a few of the same ideas, I also suggested that there be some sort of bonus/penalty for tactical positioning, as well as stances that allow you to change fighting style to fit the situation.

I have a few more ideas that would add some dynamics to the battles.

Throw attacks, basically just some special attacks that have a strong knockback effect, but only on enemies you are strong enough to throw. It would add some great ways to get the enemy where you want them for positioning, plus it is a great way to add something more than slashing and poking to the moveset.

Multi layered monsters, I love when a game has me knocking over a giant monster by attacking it's feet before I can get to it's head. Things like that add some new ways to adjust monster behavior and add to how players must stratagise, maybe you can't attack a monster until you knock something onto it to break it's hard shell or something like that.

Environmental attacks. Using old pillars and knocking a monster off a steep hill add to the ways you look at your surroundings. Suddenly that patch of dried grass becomes a possible fire trap and boulders become your new weapons from above.

Grappling hooks, great for pulling flying enemies out of the air, moving an enemy into a good tactical position, or just keeping that huge boss from pancaking your healer grappling hooks could have a great tactal purpose that is most effective if you have strong people using them.