This would solve as many issues as possible without straightup removing the warclaw from WvW (which I'd prefer, but I know is unlikely).
Would it help players move accross the map? Yes.
Would it help players avoid combat in a PvP gamemode, killing certain playstyles such as roaming? No.
Would it curb stealth one shot builds? Yes, because they'd have to reveal themselves to dimount the target.
Would players get dismounted by everything? No, there's still one dodge to get you past hostile mobs and other small obstacles.
Maybe reduce mount speed slightly as well. Thoughts?