On the surface, you're looking at a $25k profit.

Surface, non-expanding cracks in poured concrete is no big deal, same with stair-steps on blocks so long as they're not supporting a brick facade or shifting out of place.

The woman seemed quite motivated on the surface, but really wasn't as motivated as I thought. 

You’re asking for a reply that would take the better part of a day just to scrape the surface. 

On the surface, it sounds sketchy, but as others have said if the agent has the homeowner's permission then no fuss, no foul.Sometimes people just walk away and they don't care about the money. 

I was wondering, if you currently own a multi unit property (let assume 5 units, 4 with the same surface one a bit smaller),  let's say bought for $500.000 and you only sell one unit for $170.000, how the capital gain would be calculated.

Heat pumps and ACs will rust out much faster, painted surfaces won’t last as long, so upkeep will be more than a house inland. 

On the surface, and as Andy mentions, that's seems too good to be true, so there is likely some underlying factors not divulged.  

In 1990, the Tennessee state legislature gave all mineral rights to the surface owners who filed for them.

Floors: Sweep, mop, and wipe down all floor surfaces, including underneath appliances.