expand_less In ghost form, you can fly at 40 ft. per move action.  You have clumsy maneuverability, so you take a -8 on fly checks to perform special maneuvers.
Since you are incorporeal in ghost form, you can fly into solid objects or water.  The only limitation is that you must be adjacent to the surface of solid objects (so you can't pass completely through a solid block that is larger than you).  See the incorporeal special quality (copied to your constant effects), for details.