Diving into creative financing options like you’ve done shows initiative, and you're clearly thinking about the big picture.

I like the idea of a hold back until the punchlist is complete, but that doesn't prevent an unscrupulous contractor from stealing the initial deposit...

Also, I assume a 10% property management fee in my calculations and based on initial conversations.

I own a high-demand business that I've been planning on selling anyway but that sale will take a minimum of 6 months, so I can't use that for the initial purchase. 

Not only the initial fees, but there are also liquidity requirements, i.e. $300k loan needs to show $15k liquid assets, and draws typically require you to pay contractors and obtain a lien release before you can be reimbursed for the money you paid contractor.While I know there are a lot of people who use low money down loans to get started, it is risky.  

STRs specifically have supercharged our passive income goals and cut down our initial goal of a 10 yr run to get where we want to be in half. 

Actually, you were on the right track initially.

You've overcome the initial hurdle.

Aside from that, it sounds like my operation is quite a bit smaller than what you and your network operate with, but properties that are wholesaled are usually all cash or hard money, so the initial funding aspect usually isn't a roadblock.

I would invest in ugly houses that need lots of rehab work to build the equity and refi spreads needed to offset the work and preserve most/all of my initial capital.