During the hydrojet call, the technician snaked the line and suspected there was an obstruction about 50-75 feet in, so I think a fourth possibility is roots intrusion.

Negotiations were handled by my agent (Danay Guenther-Root Realty).

They used a dozer to knock them over and push out the roots as they pushed the tree to the burn pile. 

It's good to appreciate your roots and humble beginnings.

Make sure you budget for time, consultations, removal, root raking, in-fill, soil testing, compaction testing, and tree replacement costs. 

I've never heard of block walls deteriorating after long term with water-maybe something made of wood that isn't treated.To undo the sod, depends on how long it has been down and how deep the roots are.

If the mold is really bad in there you may need to pull any affected insulation out, possibly replace some of the decking, maybe the trusses are even rotting, it’s hard to say without seeing it myself but the root cause is likely lack of ventilation.

While I am definitely not against investing in places that you are not an expert in, I do believe that it would be nice to start in a city where you have some roots/knowledge.

We'll be rooting for you!

Generally, the negative behavior of one tenant is most likely the root of the problem.