Idea for you!!
How about an idiots guide to editing mesh files and still keep them usable?
outside of messing with creator settings (for lack of a better term) when ever I try to use the editing tools to make a place walkable, or unwalkable... I end up with divided segments of the zone (as in pathing only works on the west side... until I manually cross a specific point, then it only works on the east)
Editing the height and radius can help. And of course some zones (like shard's landing) you need to adjust the Y on the bounding box.
But for instance Chardok, or Heart of Fear:epicenter, are just nightmares of getting stuck or "unable to find start/destination point"
I have spent time tinking with various zone meshes in an effort to make obtaining collectables easier.... can't seem to get it to work when I use the editing tools except a few no-go zones. To many and the mesh goes blah. Try to make walkable areas and, divide the zone. And of course it doesn't help that some of the collectibles are in places of no clear path, heh.