This would allow you to defer the capital gains tax, and instead of taking a large tax hit, you would be able to use the tax to invest in a nicer property/properties.

I’ve done some research and have found that some banks will allow the seller finance portion from the seller to go towards the down payment of the loan, is that true?

A cash-out refi could allow you to set aside some funds as a reserve or at least pay down your debts so that your lines of credit (credit cards etc) can act as your emergency reserve when more bad things happen. 

This way, if vacation rental management becomes too demanding or isn’t feasible, you have an alternative strategy in place.Make sure to confirm that the HOA or association allows rentals at all.

Also, if the property doesn’t cash flow or cash flows poorly as your summary indicates, coming up with a creative financing strategy that allows for greater cash flow doesn’t necessarily make it a good purchase or investment.

I definitely want to continue in my field—not just because I enjoy it, but also because it allows me to keep investing without dipping into the cash flow from my soon to be units.

Having a "master" accounting software allows you to blend all property-specific info with general business info to see your full financial picture. 

Here’s what you need to consider:1.Related-Party Restrictions•The IRS generally doesn’t allow 1031 exchanges when both the sale and purchase involve related parties, unless both properties are held for at least two years after the exchange.

I am in a large syndication group too where GPs are not even allowed.

United Wholesale Mortgage is only lender I'm aware of that allows for $100k or less for a DSCR loan.