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. 

If you've been active in this business and actively pursuing a profit during the year, the loss the business generates could help offset other income on your tax return. 

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

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

Best thing to do is have it I a high yield savings that is generating money on your money and is very liquid when you need it.

Yes I could do a generator but that is more bother, tell the tenants to turn on the fireplace.  

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. 

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.

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.