the difference between OBE and AP is that in OBE you project into what we refer to as the real time zone, whereas in an AP you are in the astral planes, which as you say can be manipulated by intent and are also the home of many other astral beings.
for furher information please check out these forums, they are specialized on AP and OBEs. you will find experienced answers to all your questions there.
Astral Dynamics :: Index The Astral Pulse - Index