Rerouting a kitchen sink plumbing may offer temporary relief but does not address the root cause - a cracked cast iron drain pipe.  

Many plumbing issues can result from roots penetrating sewer lines which should never be the tenants responsibility 8.

The catch: we are a military family due to get orders soon so it's hard to put roots down somewhere.

Find the root cause for the late payments and address that.

Apparently the owner was also scammed with tree roots and mold in the basement when it was really cellar fungus in the corner. 

That list does cover the heavy hitters, but just to sum it up here are some that I always look for (I also get a home inspection for each property before buying it and ask my inspector to check for these things).Stuff You Can't See (aka takes a test or a professional)AsbestosLead based paintLead in the soilBuried oil tanks (if the home use to have an oil furnace)Collapsed/Rooted sewer linesPoor septic tanks (I have heard of people buying homes and finding out that a 50 gal drum is the septic tank)Stuff You Can See (or easily find out on your own)Old wiring (knob/tube, cloth, aluminum)Cast iron plumbingBroken roof raftersDry rot, termites, wet rot, and just wood support issuesMoldFuses/Multiple electric panelsSloping floorsCracked foundationsSigns of water in crawl space/basementThose are the ones just of the top of my head which can quickly add thousands of dollars to a job.

It will just lay there until the first warm days in spring and then start to root in.

Those with no employment, poor credit or evictions will be rooted out.

Many foundation problems have water as a root cause - be that infiltration in a crawl space, drainage around the site, cracked sewer line or water line.

You might want to start by locating the root cause of water damage.Does the subfloor need to be replaced?