I assume there's a commands-per-turn limit. Is it a given number, or "keep it reasonable"?
Good question, I actually had to think about this one.
Your character will accomplish as many commands as I think are possible during a given turn.
As a baseline (subject to unforeseen command sets), you can generally expect to be able to move-->perform animated action or perform non-animated action-->move.
Your last set of commands is a good example. You moved to the plant and performed an animated action (examining the plant, finding the fruit). In your next action you made a non-animated command (harvest some additional fruit) and then moved. If you had wanted to thoroughly search the plants and harvest from the second smaller bush, your move command would have not gone through, and your character would be stopped over the second bush gathering additional fruit this panel.