A professional foundation inspection to determine root cause and verify the neighbor is at fault.

This is a fairly common issue with older properties  where root structures create a dislocation in the line causing constant backups and the only remedy is replacement.

If it is a more recent situation look for the root cause and try to figure it out before you let them go. 

That will solve the root cause.

I don't do root canal on myself either! 

Most use what's called a Veeder-Root system for that.There are/were quite a few single-wall stainless tanks in use. 

I also did a sewer scope as well that showed that the roots has gotten into the sewers and needed to be replaced immediate.

Personally in my experiences we have worked with many Section 8 tenants and we have learned to be able to as you stated screen them a little bit better and root out the good from the bad so that you do have a good experience with a Section 8 tenant.

I also did a sewer scope as well that showed that the roots has gotten into the sewers and needed to be replaced immediate.

Now we were out there in April with a plumber due to roots in the sewer line, the plumber and I were there for around 4 hours he ran a camera through the lines and cut out all the roots and then ran the camera through it again and the line was clear.