First guy did the framing for walls and layout of the basement, the door frame was too small for the door so it won't fit and he did the tile without cement under it.

If I were doing it again I would seal the cement foundation with something like the kilz primer.  

Prior to placing the building in service, M pays amounts to repair cement steps, refinish wood floors, patch holes in walls, and paint the interiors and exteriors of the building.

If the siding is cement based asbestos siding,  going over it with vinyl would likely cause breakage leading to a hazard.  

That’s like saying which profession has more success a dentist or a medical dr? 

While the rental was vacant, thought it was a good time to install some windows, outside cement work.

Examples would be karate school, doctor office, vet animal office, restaurant, dentist, salon, barber shop, gym,etc.People like getting out and living.

Same goes for doctors, dentists who own their own practice etc etc.So if you don’t want to partner, don’t have millions and don’t earn 100s of thousands at your day job, and don’t have enough equity in other properties, you’ve got one more option..Seller financing.

@Jesse Stephenson cement it in and get a stout metal pole.

Any pros familiar with converting single family homes to small commercial like dentists, lawyers, etc.?