We do want to settle in a little bit here while continuing to do our homework, but hope to get into something in the next 6-12 months.With the way interest rates are looking now and what little I see on public listings, I think a smaller multi-family that needs a little rehab would be the best bet. 

We’ve tried other platforms on the market, but the message delivery rates were very low compared to the 85%+ I get here.

That is the best option if you are truly trying to help a family member.you cannot get control of the mortgage, you can do sub2 but you are not in control, the bank could call it due if they see the property transfers title.The other way is for you to buy it from them at market rate, then rent it back to them at market rate.

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. 

Rent is below market rate for the general area.

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.