I don't pop regen on pull, but try to stoneskin the tank before their pull (I interrupt SS if it looks like it'll go off during pull).
I also tell tanks to click regen off before pulls if they wish.
My only aggro issue is Medica II when solo healing HM Primal. （￣□￣；)
Then it is stressful when someone yells at you to Shroud when it's on CD.