- remove existing tile - remove drywall in surround and window area to the ceiling - replace drywall with hardibacker redgard hardibacker large porcelain tiles (16x16, 12x24) with smallest grout spacing possible- highest quality caulk that is mildew-resistant - tile floors, 4" base/behind/beside toilet, in addition to tub surround all the way to ceiling - angle tiles away from block window - re-install shower curtain rod  - replace fan/light with higher-performance model with humidity sensor - inspect fan ventiliation to confirm vent going through ceiling - inspect bath, sink, toilet plumbing and waste drainpipes - add quarter turn water shut-off valve - replace bath fixtures to single stem handle - replace bath drain with grid drain

I ended up passing on this deal (they also gave me resistance on the Estoppels, which I did ask for), but I like all of your suggestions.

He wants me to just take over his loan, but I am hitting resistance with lenders.

Or wait it out if they will not cooperate....moving is a pita so don’t be too surprised if they resist, hoping the other side takes it.

Many people automatically think electric resistance baseboards (or electrical coils in a central air-handler), but your ancillary heat could be easily fuelled with natural gas, propane, oil or another fuel.Presuming your use of "furnace" means a forced air furnace and not a boiler and hydronic heat, you have the option of adding a heat pump with an exchanger insert in the plenum of your existing ductwork.  

I am trying to help you, ( I do not want anything)  but you seem to be resisting.

Not to mention the loss of jobs with the robot built houses and the less maintenance needed on a concrete house.I feel there will be a large governmental resistance to them because of what they are going to do to the economy but the cat is out of the Bag.

Sorry, couldn't resist!  

My partner and I own several MH/RV parks in the state of Arizona and are focused on the creation of recession resistant cash flow for our investment fund. 

You could resist it with section 8 after the renovations are complete for more money.