Re-pipe under floor so drains run to sanitary sewer.

We get it turned off after the entire system drains into the basement below.

I made the mistake a few years ago letting my emotions get the best of me and ended up throwing money down the drain seeking legal recourse when I was better served simply moving on.

Your biggest risk if you execute the plan will be running out of money in retirement, either due to natural longevity and/or later health issues draining your resources.  

Other things he did.1) did not put a spacer between cabinets, so if I fix that the granite countertop slab gets tossed because the measurments changed and it will be shorter than the cabinets.2) He tried removing a rusted shut 70 year old clean-out drain cap, and caused it to pop off (under pressure) and flood under the cabinets.

The occasional basement leak, which is common in my areas in all houses and has a floor drain.  

I recently purchased a property and during the inspection the inspector said the dishwasher drain was hooked up to the garbage disposal.

Multiple times I was called over to fix doors that had been pulled off the hinges, Outlet covers that had been pulled off and broken, towel rods and toilet paper holders pulled off of walls, stuff put down the drains causing back ups.

. (# and size of offices, bathrooms,doors, windows, floor drains, lights, truck docks).If you make an educated guess you will likely still be tearing out or changing brand new walls and concrete, but if you leave it incomplete it is harder to rent.Plan on some extra expense for those tenant improvements.

The hot tub should be drained and filled and sanitized after each guest.