I believe I mentioned my two-cents on how flightor is one of my worries about farm-botting in one of these earlier pages. That probably seems rather complex though, and maybe a little greedy on our end

. However in terms of navigation, I'm surprised they haven't added portals and things to the Nav already. It's weird too because for example the Undercity to/from Silvermoon portal doesn't work with the nav, but a very similar chain of portals used for 1 quest are fully navigable by the bot east of Silvermoon.
At this point though I'm not sure what other ideas I could come up with, seeing as how you've covered most of the bases while having a very firm base in nature-bound random gathering.