You cannot use rental income above your mortgage payment to help qualify for a larger mortgage, but you can utilize 100% of the lease income to offset so that should help you qualify for more of a mortgage. 

Interest rates and points are not the only criteria upon which to base a decision; length of loan, amortization and if you can get it “loan assumability” especially with no qualifying and no rate escalation could e much more important. 

The whole scheme was buy a foreclosure, "sell" it back to someone that can't qualify for traditional financing with seller financing at a higher rate, once note is "performing" you can sell the note and make a lot of money. 

Also remember just because a loan may qualify as being assumable the lender will go through a thorough underwriting process to confirm you meet eligibility for the loan.I have seen a guru teaching people with poor credit to go after these types of loans and it’s unfortunate as many would most likely not qualify.

Basically you stay working there and rollover funds into another qualified plan.   

Tell tenants "if you don't apply, qualify and get assistance, you can be evicted".

They're good to have open access to capital/cash/equity to a property ahead of time so you can execute a deal or purchase when the time comes on a split second decision (versus having to apply to a loan at that time which might take 20-45 days to get approved/closed/etc plus by that time you dont know what your future income/credit/assets will be like in order to qualify anyway).The second use is sleep at night factor and having a reserve of capital in the event an emergency event occurs in life.For these two reasons is why I use lines of credit.

To add to @Patrick Roberts post - this loan type will require you to qualify with income and liabilities = DTI ratio, which will include the rents you pay to your NV home.

@Shelby Ek Do you need to activate the utilities in order to qualify for the loan you are getting?

Your first step will be to talk to several lenders to find out what you qualify for.