Hopefully, one of them can reach out to provide further assistance and insight into what you're trying to accomplish in real estate. 

Quote from @Dereck Olson: Hi Nicholas,  Just a thought from the possible tenant's perspective, but filling out a prequalification form and/or providing personal information before they have even seen a place and know if they will be interested in living in the property might be a bit too much to ask. 

Ive asked them to provide Renter's Insurance.

I interpretttev @Alan Asriants statement different than you but agree it is not clear   He could be indicating pools, basements, sunrooms do not provide a means for an extra tenant.  

The seller was willing to take a secondary position on other property assets and provide a 3yr 4% interest on his loan.

He could provide you with some good insight in and around the area!

You are considering putting a tiny home on your existing property as an ADU or using that money to save up and buy the next investment property and wondering which would be the wiser choice.I think ADUs can help provide additional, much needed, housing.

Now the post test reveals I have pvc sewer line leaks under the concrete foundation. plumber has found multiple breaks in the line which need to be repaired and has provided an estimate for tunneling under the house and replacing entire 45ft main line!

My conclusion is that take the provided ROI calculations from REI as purely estimates.

He/she can also provide guidance / consulting throughout the year.Best of luck