I am working on a whirlpool tube and am trying to get ideas for incorporating an access panel in the front of the tub which has to have 1 step and is covered completely in tile. Problem-left side is the shower wall, right side is bed room closet, back is exterior wall. Should I maybe look to put it in the Closet? Keep in mind I will have an on-demand hot water heater in this closet. I need an access panel to get at the pump and drain. Should i have 2?

Yes, put it in the closet. I have a similar tub - one step up, area covered in tile. On mine the access is through the wall of the adjoining bedroom. If I had any 'druthers' I'd rather they'd made the access bigger when the house was built. The access door is very small and it would be very difficult to to actually do any usefull work in that space. I recommend you make the access as large as is practical for you.