Secondly, those poor guys would not have to die when cutlers got side tracked to some small group of people hanging around as i was passing by with the wind in my hair.
Lastly, I can see a great potential for griefing here

walk into roots, collect the nasties, and PVP using mobs as a weapons, they cant touch you because you are too fast but they will get sidetracked if someone else is standing near by.
In short, I think ALL forms of fighting and teleportation should be allowed.
The only exclusion to the rule might be foraging, it pains me to imagine what kind of animation would be needed to forage while sitting on a mount.
Just my 2C