Flipping/wholesaling also have high returns but are not considered passive at all.I own a couple of properties in 29 Palms that were purchased a couple years back and the returns have been good, but they have had some headaches with turnover and prolonged vacancy. 

My passion is modifying residential places for senior, so they can prolong their life in their own environment, and eventually develop my own senior residential complex.

People that are squatters and know how to find the name of the previous owner to create a false lease usually know the system and know what to do to prolong their stay - like responding on the last day.

That prolongs the closing process 3 additional weeks now i'm really skeptical about the seller now Weeks later with daily communication to insure the progress is moving forward.

Most settle before that (either agree on prolong stay or reduce the rent owe or both).

People that work hard don’t stop, and people that go unemployed for prolonged periods and mooch or work the system also don’t stop.

Prolonged unemployment will promise home loss.As for flippers, if the homes do not have rapid appreciation the profit made if any is not worth the effort.

Prolonged vacancies on rentals kill numbers a lot more than a $50 reduction in your desired rent price to get it filled sooner.

I did a quick Google search and read a bit about them... and it sounds like there is a filter that should be cleaned on a monthly basis to prolong their life and decrease long-term maintenance costs. 

The asbestos is an issue but you can prolong that or deal with that a couple different ways and I won't get into that here.2.