: Should I set the new tub on the (plywood) subfloor
: or the wonderboard or the floor tile? All three options are available to me. Which option will limit
: the possibility of future damage resulting from water splashing out of the tub & down the sides?

Erick,
While setting the tub on the tile will help with water, it is really not in the proper order. The floor is usually the last thing done in the room with the exception of the base mold.

If the floor is out of level, what better way to hide that than to set the tub to level with shims and hide the increasing gap with floor material.

Between the tub and floor, it should be caulked. That way the water from the tub, will roll out onto the floor where it's not likely to do damage.