He could have sold it to any investor, but he called me because he trusted I would handle it with care and respect his wishes.

As someone who has read Harry Potter, it seems the best way to get the attention of the landlord is to send a scary looking giant to their home residence with a kindly worded letter.More seriously, I was on the other side of the coin previously where my wife put the ads up under her accounts instead of mine, so I couldn't check them without getting on her phone and I was inundated with people looking to see the property (probably 50 over a 5 day period) and was trying to send semi-personalized notes to each one--and it all ended up being too much to handle and I ended up ghosting or not replying to many people after I found an applicant. 

They aren't spending their own money, so they are less likely to take care of the rental or follow rules.

The sad part of this story is if any other taxpayer failed to update their address and a lien was sold, nobody would pay any attention to reversing that sale.

Any competent real estate attorney can take care of this for you. 

I took a few years out of work to take care and spend time with a family member whp passed, so I have only been working for a year now.

I don't really care to be frank, whenever I see a post I can provide input on I interact with it. 

I dont care who pays it or how... if its not paid in full, they get evicted.

Their strategy focused on targeting traveling nurses, a niche market with reliable demand.As for repeating the process in the same city, it's doable but requires careful planning.

Who cares?