I can't see any possible situation where someone would liquidate a property at a cap rate of 27%.

I am presuming you are not taking a secured lien on real property (you should)...I would not do this deal unless you are prepared to reduce your 100k liquid to 5k and monthly payments of 833.33 a month for who knows how long.If I'm a company 60 days away from a 12 million dollar infusion, I don't put myself in the position of needing a 100,000 band-aid.  

Prove to yourself that you know what to do with your limited time and then when you have MORE time you know with confidence that you know what to do with it.If your plans are to liquidate your IRA why not use only 1/2 and do the REI side hustle to find a cash partner to believe in you to fill the other half.  

What are some creative ways to structure this deal without completely liquidating my capital?

Of course, if you find a friend or family member that has some liquidity and wants to help, they may be very willing to agree to a 3-6% interest rate, and be flexible with the loan term.  

Option #1 makes the most tax sense as I'll be paying less in taxes and at least still have some minimal access to the money, but I *hate* that option as I much prefer liquidity.

After seeing the investors I work for make profits on liquidation of their assets I started to explore my investing options.

Saw an interesting job where they coated the old stucco with a spray on cork finish..very impressive.https://buyspraycork.com/

One of the ways is to get a deposit with the lease agreement, and a document signed that says if the tenant doesn't perform, that deposit is your liquidated damages.

The pest guys come in an spray, they don't do any real prep.