You must base your design on the location of the waste stack if you don't intend to do major surgery on your property to put your bathroom in.

A 3 ring binder maybe with the plastic 3 hole sheets filled with info.

If mold is on the joist that would be no problem to clean, just needs some equipment and on the sub floor i believe pending on how severe it is you may just get away with a cleaning with specialized chemical thats stronger than bleach (I know the name but cant remember how its spelled) , as well as a negative air machine, some duct tape, plastic sheething, tyvek suits, gloves and other ppe needed for the workers or it could be severe enough that the floors would have to come up (I know you dont like the sounds of that) and possibly trace it up the walls if any moisture wicked its way up sheetrock and the insulation thats in the walls?...

The wife just had knee surgery so our planning our first meeting for the first Tuesday in Feb at 8pm. 

Chlorine constantly escapes through the plastic walls of its containers. (4) The ionic structure of bleach prevents Chlorine from penetrating into porous materials such as drywall and wood---it just stays on the outside surface, whereas mold has enzyme roots growing inside the porous construction materials---however, the water content penetrates and actually FEEDS the mold---this is why a few days later you will notice darker, more concentrated mold growing (faster) on the bleached area

Home Depot sells a scraper that has an attachment for a plastic bag to catch the debris as it falls.

I usually put down cheap plastic before I begin.  

I see your point---you might let your mechanic check under the hood of your Porshe, but would understandable shy away from the notion of letting him do open heart surgery on you.

I would make it seem like you just bought the old fridge maybe wrap it in some plastic and clean it real good.

@Vincent DangIf you were going to need back surgery, would you hire a surgeon or try to learn how to be a surgeon yourself?