I would mention to Tenant B that I was visiting Tenant A and smelled what seemed like marijuana smoke coming from their side and remind them there is no smoking permitted inside the house.

And the owner is very responsive to questions or issues (emailed him at night and received a reply within a few hours).  

The letter also states the total non-rent items currently owed by the tenant, such as accumulated late fees or repair charges.Also very important, the tenant states they have no unresolved issues with their current landlord, except as listed in a space provided, and they have no current plans to cancel their lease under the Service Members Civil Relief Act or for any other reason. 

No issues with MTRs in duplexes, triplexes, and quads.

Most negative comments come from competitors, those nitpicking minor issues, or people who haven’t worked with the company at all.

Issue:  computer-generated random phone numbers for outgoing calls. 

If there are any legal issues that I have to worry about etc. 

Can anyone recommend good companies to root cause  and implement solution to fix this issue?

My understanding is that the ballpark standard of "unless it would be outrageously tough" (something along those lines) is what applies if you're doing a rehab, seeking new permits, doing structural changes anyways, and things of that nature.For existing pre-ADA structures, my understanding is that the standard is more along the lines of "if it can be easily/cheaply done, you have to do it."

The issue I have is that I am struggling to find serious partners to work with.