Action groups:
1 toggles the docking port on the very top
2 toggles the lander's aerospike engines. I recommend activating them just after launch (they have fuel lines to draw from the launch stage first) and deactivating them once you drop the first set of aspargus-staged engines.
3 toggles the rear aerospike on the rover itself.
4 toggles the engines underneath the rover for VTOL.
5 toggles the rover's landing legs that are for...landing. What I mean is, they don't toggle the landing legs mounted on top of the rover, which are for flipping it upright in case of any accidents.
There's directed RCS on the nose and rear of the rover to keep it balanced if its center of mass changes too much when fuel is drained unevenly. So far I haven't really needed it, the reaction wheels are really strong.
Edit: Couple more things; 1) make sure you only control it in docking mode, as the reaction wheels have enough force to flip it and 2) it has a drone piece on top of it, right under the docking port, for easier control orientation during VTOL.