Our bathroom is a rear bath. We decided to gut it. My husband took out the sink and is recessing it 6 in in the closet. We want to use FRP on all walls. Can it be glued directly to the rigid foam. Also, we would like to scoot toilet over feom showe. Will we have to drop the tank and move it over too, or can we seal that hole in tank and cut a new one and put in new flange?