Guess what this does have an APM Clone flight controller. You can use mission planner.
o, just to flesh out some answers to the points that you raise.
The Simtoo drone here uses the ArduCopter code in an APM 2.52 board and utilises the same flight modes that any other copter running this will use. The software version on mind is Ardupilot 3.2.1 (Which they brand as ACSim 3.2.1)
Altitude is via the barometer in the autopilot and unfortunately, GPS height is not taken into account, thus that's why it won't change altitude when following up and down a hill. Shame but the same affliction as all the others on the same code, plus GPS is not particularly accurate in height.