Obviously, there are no guaranties, but there aren't in the fix and flip market or stock market either. 

You can get a HML to purchase the property on a short term loan then refi out or you can find a lender willing to do a 30 year mortgage on the property as well it really depends on the scenario but occupied properties aren't typically an issue as long as the occupant isn't the owner

Also, make sure you aren't going to be receiving any fines in your area for putting them out.

Moreover, I cannot believe the Cohens aren't serving LONG time in jail!!!

I would buy a multi, 60’s and 70’s aren’t that old.We have 1880’s builds here in Minneapolis!

After all, you aren't going to get someone to sell it for a loss (probably) so need to know that as well.

The humidity levels in units 2 and 3 aren't nearly as bad as on the first floor unit (which is the one I'm currently house hacking). 

(other people here know how to do it and maybe this is more you...you aren't wrong, just know what the risks are).

Also the owner has offered the tenant cash for key but they aren't willing to move. 

If they aren't from the 1920's, they are even older.