We pay the mortgage on our rental property with the rents paid by the tenant. 

I have done enough research to know that it may be wise to invest money that gets a higher rate of return than my mortgage interest paid, but that's the extent of my knowledge at this point.

As we know housing doesn't paid for more garage space, with the proposed cut around $9.5 billion in 2018, my rent is not getting SAFMR (small area fare market rent) if I include 3 car garage.   

The land is completely paid for.

And once it reaches 60 days and I haven't gotten paid, is the landlord in his legal right to call a sheriff to evict me?

Paid him out at the end of the day. 

Sounds suspect with a $938 monthly fee.You should get a real estate agent to submit the offer, its free to you, the agent commission is paid by the seller.

It is structured similarly to a HELOC but meant to be paid off in a short period of time - when you sell your current primary home. 

It’s going to be difficult to really push the ARV higher than what you paid unless you’re willing to wait 6-12 months

Also, if the property is paid for, you will have a net increase personal income from the rent, with potentially higher taxes overall.