All flooring is tile, with granite surfaces in kitchen and baths.  

Check the following: storm pond, storm drain, road surface and specs, sewer, water, electric, internet, road access, fire hydrant, soil compaction, setbacks.

Exterior paint, window and door trim and painted surfaces.

On the surface, it would seem to be a ridiculous standard, but often the rent and the expenses on both properties will give nearly the same monthly return.

Then you have a water-resistant surface that will not swell up and look damaged when people put cleaners there or have the inevitable drain leaks.

Once you add layer over layer, are you creating uneven surfaces? 

If I was a betting man, and had only this picture to make my bet, I would say that this is an freeze-thaw crack - pressure from the soil outside the foundation pushing inward (hence the semi-circular pattern - not stair-step, not vertical or horizontal), so it might be a matter of some exterior grading/drainage work followed by an epoxy grout crack filler repair to remove moisture.I recommend you get it checked out - put a contingency in the contract that covers your bases, so you're only out a couple hundred bucks for a structural inspector. 

Baking soda has an amazing amount of very gentle abrasiveness, which should lift any surface stains that remain from the bleaching.  

This is where the opportunities will surface.

I've only begun to scratch the surface and already I find it all very informative.