It would be great to have a hotkey for rotatating and snapping the camera 90deg to each cardinal direction.

That's effectively how I do manual rotation, it just takes a bit more manual work. It would be nice to just be able to quickly rotate through fixed orientations as the manual rotations in between those directions is generally not as useful (at least to me). This would be really nice while needing to rotate the camera in combat.

I don't see this as a replaceemnt, more as a preference setting for the existing keys so the behaviour could be switched between. I'm sure some folks like it as is.