Looks like I'm late to the party :-)  Lots of good discussions.

Just a couple of notes from me:

Doors: I've actually used local rotations to figure out how much a door is open (in aicombat).  i.e. I needed more information than simply knowing whether a door is being opened or closed.  I suppose the code could be re-written to use enums instead, but may lose some flexibility.

PathFinding: I think we need several variants of pathfinding.  We currently only have pathgrid based A*, and it is mostly written (IMHO) to cater for NPC's.  We need another pathfinder variant for external cells without any pathgrids (currently you get straight line path back from buildPath) and possibly a more complicated one for aitravel (I was investigating D* which is resource heavy but should be fine if only a few actors are using it)