I've been working on a business plan for it using the senior living housing model without the ADA/medical component. 

Consider calling the ADA hotline and ask your questions there.

This was accomplished by converting the entire garage space into beds and bathrooms( including one ADA bathroom), and converting the master bed and bath area into two Jr sized master bedrooms and baths.

Should I consider an ADA Bath?  

I dont want to ask any questions about it. my question is there any risk in having a disabled person in a non ADA unit?

Maybe a walk in shower with the window sealed up outside and inside and some nice sheet vinyl on the floor.Add a hand held shower head on a metal hose for hygienic purposes and to make cleaning the shower easier--many of them cost little, and an ADA bar or two to help prevent falls.

Take a look at bathrooms to make sure you can convert them to ADA accessible. 

You will need to make the entire property ADA compliant to get wheelchairs up stairs, to get wheelchairs through every doorway inside the house and you need bathrooms large enough so wheelchairs can get to the toilets and sinks..You need shower stalls large enough you can roll a wheelchair inside. 

As a result, I paid approx $18,000 remodel, repairs, restrooms, electrical, lighting, and ADA compliant.

Because of our location and amenities plus the fact that these are ground level garden-style homes across from a rapid transit station we are exploring the idea of converting to full ADA spec handicapped accessible.