it sounds like a crazily useful tool! visualization of hidden systems is important, manual overriding of auto generated mesh is great, especially if it can be saved and then loaded and updated fast during gameplay (to achieve destructable/buildable environment).
I want to make some simple games beside my editor and rts project to avoid getting bored, but I would need a simple to use and good navmesh pathfinder, like in Esenthel but with collision avoidance what you completed earlier.
I hope you could solve the hmp mesh problems too.