Use tools like AirDNA or Mashvisor to provide market data on projected rental income and occupancy rates, and make sure your lender works with appraisers familiar with short-term rentals.

especially now with rates up.

How much do they want you to to pay, to pay off one of the mortgages (or both of their existing mortgages)? 

Tenants are more likely to trust landlords who demonstrate a commitment to fairness and legal standards, leading to better occupancy rates and long-term success.Adapting to regulatory changes is an essential part of being a successful real estate investor.

Our last deal we engaged a mortgage broker that also brought a Private Equity LP (Limited Partner) to the deal. 

Instead of evicting them, i was thinking is there some way that I could rent it back to him for very cheap (mainly to cover just the taxes/ insurance) ie 2k a year rather than the going rate of 2k a month for similar properties.

Rent is below market rate for the general area.

Most mortgage companies will not call loan due if payments are current but you do run that risk and need to be prepared to payoff or refi at a moments notice.

You should be able to claim the ENTIRE mortgage interest as they let you on primary homes.

What is the compelling reason for them to pick you, with your competitive rates, over someone else they've already been using with competitive rates?