Maybe a brain massage is better than picking?

The inexpensive long-term fix is to smash them out, replace with a fiberglass/acrylic tub that covers the original footprint of the tub (usually you can get away with 60x30, sometimes you will need 60x32), and do a glue-up acrylic surround to cover up the existing tilework.

We now have a nail technician, esthetician renting the studio, massage therapist, hair stylist, and both apartments rented.  

I want the financial freedom to eat as many crablegs as I can during this lifetime, and to have multiple people massage every single one of my extremities (just 4 people... the fifth one is off limits ... besides my left arm hurts to no one touches my lefty ).

And a massage business (both units i havent seen) Both were paying extremely low rent amounts around 300 a month each.  3 units for sure need to be brought up to higher standards. im convinced this is a shiny piece of coal needing to be worked, but still im concerned for the previous owner refusing a inspection. 

Quote from @Atul Mohlajee: I suspect it's a sewing machine, a foot massager, or some other innocent device.

Your renters are constantly building up the topsoil by farming in a "land regenerative" way using livestock to massage the soil. 

We put in acrylic counter tops with built in sinks, 2 piece fiberglass shower, no garbage disposal, no W/D, etc etc.

You have to get her buy in with some kind of trade off like bigger house plus roommate or not her dream home and no roommate, or of the $1000 rent she can keep $300 for a monthly house maid and two hour massage or $200 shopping spree or something.

Guesstimate breakdown:Roof 1000sq ft house 6kFloors wood sand and recoat 650 sq ft 1300Vinyl 300 sq ft square tiles 900Countertop 1kBacksplash 650Paint interior 800Bathroom new:Shower 1kValve/trim, etc 150Toilet 125Sink vanity mirror 175Bath#2 1.5k (cant remember so new acrylic tub surround included).Replumb house with pex, 2 new bath valves, shutoffs, 4kCarpet bedrooms $600New outlets, switches and plates by handyman $800.Misc whatever is left.No insulation??????