We took loans under the individual name rather the LLC, would moving under LLC trigger a sale on paper?

This would lower your monthly payment and free up more cash flow, but it would also slow down your ability to acquire more rental properties.Another option is splitting the $30K across multiple small rental properties.

In the end, it may be the same amount of money or more, but it will just have to be structured differently as you navigate the shifting market.Northwest Valley would be a good option. 

Expenses are about to go up considerably.

When it's sold it will be taxed as capital gains tax and may also have some unrecaptured depreciation which is capped at 25% and  recaptured depreciation as well which can be up to your ordinary income tax rate.

Looking to ramp up my business by advertising, specifically on Facebook to start.

You might have other options to explore to drum up liquidity (HELOC, Margin Loan, Policy Loan, etc) that can supplement your HYSA in the DP.

Then the seller gets that exact amount for the property at times (it's a low percentage but it happens).

As for the apps to use, Innago has been pretty great for me.

Quote from @Dennis McNeely: In a sandwich lease option, the investor exercises their option with the property owner to purchase the property when the tenant-buyer indicates they're ready to exercise their option and purchases the property.