Often times someone passes their NMLS test, hangs their license, does a few Fannie/Freddie deals, then tries to get into investor lending.

If you are going to test the market with a new standard, be patient.  

The guru of that particular year will create some secret variation to a time-tested list of tactics that is the flavor of the weak and pretend like this is some new secret invention, perhaps inventing new language to describe tactics that have been around for years. - In the unlikely event that you get a lead, A "motivated seller" who will work with an 18 year old to sell their home, is likely someone dealing with death, disease, divorce, or disaster.

You can test this, by asking some to SHOW you how they calculate ROI, Cap Rates, Cash-on-Cash, etc., for their clients.Many will say, "that's the investor's problem".They are correct because an investor should NOT rely anyone else to run their numbers.So, then what exactly makes them investor-friendly?

Although these platforms tend to accept bigger deals from sponsors with a lot of experience.

I want this to be acceptable long term if I keep this method of financing. 

If I were you, I'd pass on this property and look for something else (and I suggest a 3 BR) under $80 that you can put a little rehab into, unless insurance pays your family member a bunch of money and they accept a much lower price. 

Ironically some of the best deals come from properties that once failed a perc test and are considered unbuildable for that reason alone.  

So i put in an offer for 10% down conventional loan, $530,000 with 10k back to me for closing costs and it was accepted right away.

@Jonathan B.Assuming you pass the "material participation" test for 2023 and did not use the property yourself (or used very little), you should be able to treat it as an STR for 2023, including bonus depreciation.