Here's one I have on occasion. If I use Assault and my pet is not where it is supposed to be due to poor pathing then my Assault timer is reset and my command has no effect. Why can't I simply get an error message instead? The Assault recast time isn't lengthy, but sometimes every second counts.

Also, why is the pathing so poor for Avatars and other pets? Why do they see a slight bump in the terrain that doesn't impede progress at all as an obstacle to path around? It's not as though this sort of non-static terrain was added after pets were implemented. They should have been coded with it in mind should they not?