I am very late to the party, but I agree, Shove should be an action.
I use it very rarely, only when I think it makes sense, e.g. when the opponent is standing on the brink of a cliff.
(Most times, I don't even try it with my player characters, because my strength 8 Tavs would only manage to make their enemies laugh. And why get your hands dirty when you can cast thunderwave?)
