Hello all you smart people! I am going to be installing a 36x36 neo-round corner shower with a 12" off-center drain. Where is the best place to position the valve, distance from the corner wall? Additionally, I want to install a rainfall shower head that attaches to the wall (not the ceiling), where should the shower head head position be from the corner wall? Should the shower head be directly over the valve? Also, how far out from the wall should the shower head be? Should it 12 inches to match the off-center drain. I appreciate all the advice I can get before I start drilling holes and regret my decisions lol.