I do know regen gets stronger with mind (since your effectively increasing your healing power). As for Pie for refresh I never checked that easy way to test it might be to buy a potion with +pie for 15sec then use shroud once w/o it, check the refresh rate, then 2 min later pop the potion and try it again. (I think theres a +pie potion but i never really checked don't normally use potions)