SRD said:You project your astral self onto the Astral Plane, leaving your physical body behind on the Material Plane in a state of suspended animation. The spell projects an astral copy of you and all you wear or carry onto the Astral Plane. Since the Astral Plane touches upon other planes, you can travel astrally to any of these other planes as you will. To enter one, you leave the Astral Plane, forming a new physical body (and equipment) on the plane of existence you have chosen to enter.
Okay. So, you can project yourself into the Astral. You can then 'travel astrally to other planes as you will'. Does this require an existing means of access (a portal, a color pool, hitching a ride on an astral conduit), or is the ability to shift to another plane that's coterminous with the Astral simply a feature of Astral Projection? If the later, how much precision do you have in your point of arrival? And is there anything here to prevent a caster from casting Astral Projection, 'traveling astrally' back to the plane where they started, and then manifesting a new body there?