How to prevent most speed run exploits:
Speed running isnt an exploit unless you are abusing pathing bugs or the terrain to skip most of the instance. If you are simply running through and killing things fast, and jumping over walls that were obviously meant to be jumped over, onto terrain below, then again, no exploit exists.
If you are wall jumping, or bugging mobs on terrain, then having a mesmer port you to a certain location, then yes, that would be an exploit.