You're preaching to the choir here!
I also use Blender (or rather, am
attempting to use it) for adding animation for import to a flight simulator. But Blender, even the newer 2.5x versions, is like going to the dentist for a root canal. Complete information overload!!! There is NO WAY I'll ever use it for basic mesh building or texturing.... AC3D is so much more easy to use and work with.
However, it was never planned for AC3D to be a full-featured animator like Max or Blender or Maya. Unfortunately we have to live with that decision.
The X-Plane tools were developed by a 3rd party and grafted onto AC3D for that specific engine. There isn't much support beyond the ability to put those tools into the AC3D interface, I'm afraid.