I have not thought of using DTI instead of 3x the monthly rental amount in order to qualify an applicants income, but you made a great point regarding the priority that tenants might give a car payment.

The only way they would seriously consider a higher offer from an unqualified buyer is if they have no offers from better qualified buyers and their back is against a wall. 

I am not a tax or legal professional so please take this to someone much more qualified.

While some buyers may shy away from the 7.125% interest rate, others who are familiar with the "Subject-To" strategy or are more flexible on financing terms may see it as an opportunity to acquire a property with decent equity and no need to qualify for traditional financing.

Use an agent to help you get qualified tenants and documentation in order.

This extra road frontage now also qualifies my property to be able to be legally converted into a triplex from a duplex.

The rules are more complicated than your one sentence, and even Tom did not have the time to explain all of them on his podcast. 500 hours is one way to qualify for material  participation, and there are other ways.

If you don’t have a large down payment saved up, don’t worry—there are plenty of options available . . .”A trusted lender will go over the various loan types with you, any down payment requirements on those, and down payment assistance programs you may qualify for.

You qualify due to their experience and then now you have that experience too.

Do you have an idea of the long-term rental amount, and would that be sufficient to meet the DSCR ratio needed to qualify for the loan?