DSCR will help if you are tapped out of conventional loans and you don't qualify for a traditional loan based on your personal DTI.

Sounds like the person knew what was going on with their credit report as they have filed reports in the past. 

Is 10-15 miles too big of an area when determining the unit count per person?

I personally don't like the idea of using OPM as is often recommended for people without their own capital.

Have the tenants take and send pictures of any maintenance items and video chat with the repair person as needed.If you ever get in a situation where you just feel like you can't do it or don't want to do it, you can always put a PM in place at any time. 

Have met him personally a couple times and he is just a great guy all around. 

She'd probably be able to put you on the line as a co-borrower.I've done this personally and it's been great for me and my situation!

This could give you the cash you need for the purchase and also eliminate your personal guarantee for the loans.

More due diligence and follow up, does this person have a job that's consistent for at least a year?

Sounds like it might be doable, especially since you have already experienced what it would be like.