I was told that the sewer lines from the house to the street can possibly get clogged / or damaged by tree roots which is impossible to tell during a home inspection unless a sewer line camera is ran down the sewer line to detect the problem.

I get pumped for people like you and root sincerely for your success.

The plumber stated that there were roots and about 6ft of "flushable" wipes that were blocking the pipes.

We have to remove the entire front porch (structural damage due to roots) and will be removing all of the columns.

Also don’t under-estimate the cost of tree work, that gets expensive and it’s possible roots have grown into the sewer line or foundation.

Neither the roots nor the branches encroach on his property at all and my H was trying to understand why he wanted this tree down, but the guy either wouldn't tell him or couldn't tell him because (we think) there might be mental illness going on.Then the guy starts threatening that we better take the tree down or he'll call the city inspector because he "knows what they did to that house". 

Do I favor someone who has roots in the area (i.e., has lived locally longer) or who has more than one positive former landlord reference over someone who has a higher credit score or a perfectly clean record?

Question: why are they treating the symptom (application screening policies) and not the root cause (racist laws and justice system)?

For example, my lease says that "The tenant shall be charged for repair of drain blockages or stoppages unless caused by defective plumbing parts or tree roots invading sewer lines."  

It’s not doing your foundation and good with roots and water.