(Many people just assume it'll be fully tax-free because they lived in it somewhere)

I manage my own portfolio and have worked as a PM for a very successful individual but have never considered managing other peoples properties.

You can use other people's money if the numbers work.

If the applicant comes from the pool of people that I or my tenants know, I use real estate as a way to give back as many of my tenants will not qualify credit wise or may even have a criminal background or would struggle for another reason if I were to just stick to the "background/credit check" criteria. 

People doing crazy stuff lately.

I have been in many properties where private pay people rented and trashed the place. 

Lots of people who have trailers don't own the property they are on and sell them.As for the owner of the land expecting tenants to do repairs-there shouldn't be many repairs required to the land, just the trailer that is on it (which your grandmother owns and should be responsible for maintaining). 

My first home was 6% and my wifes was 8%, so people looking at 7% today as crazy - that was normal.

Also, do you have 2 people per room, or just one person? 

Too often, I just hear people say they are "looking for a good deal", but defining that good deal in a specific area makes it much easier to spot.