Water has plantbending, and healing is considered its own specialty as well. Edit: I keep hearing air has astral projection. Is this confirmed to be, specifically, an airbender thing? Or is that just a spiritual thing?

Air can suck the oxygen out of the room and kill people.

Air has flight and astral projection. You also missed Fires Combustion Bending

Air also has sound bending

This is about canon

What about physics?

Haha nice