Motivated FSBO ( the classic "good person in a bad situation" related to medical health ).

In addition, check with the state/county department of environmental health and/or environmental quality to see historical records associated with health violations. 

Consulting, law, accounting, health professionals, artistic performers, athletes, etc. 

I don't have much experience with VA, but, from my research there isnt anything specific in regards to asbestos that would disqualify the property. the only exception would be deteriorating insulation, etc. that would pose a health hazard.I would still advise you to do your own research as I have no personal experience with this.

The floor area for an accessory dwelling unit shall not exceed 30 percent of the residential floor area of the primary dwelling or 600 square feet, whichever is less, and minimum area of 150 square feet, or as specified in Section 17958.1 of the California Health and Safety Code.6.

He had some health issues and I think that was the final motivation for him to dipose of the property.

If he will be utilized to check the health of the association, bylaws, etc, you can anticipate a bill of in excess of $3000Experienced investors have offer forms they fill out themselves, but unless the state has a promulgated contract, you will be foolish not to engage legal counsel.

However, both his and his wife's health condition has worsened since the summer and he knows he needs to sell.

You have to do your interior renovations as tenants move, or leases expire and you give the tenant notice your not going to renew their lease.In really bad properties, you may need to kick out a building at time, which can be done with notice as long as your doing it for health and safety reasons, or the entire property. 

I hope that you find 2019 to be full of success and good health.