Do I need this to help reduce my risk on supply chain things?

Spoke to a few lenders and apartment investors, I learned the average time it took to close a deal 24 months ago was about 90 days and this reduced to about 60 days in the last 12 months.

Some lawyers use drop and swaps to reduce the likelihood of those but I am not an attorney and cannot advise.

As far as tapping into your equity, HELOC is a very popular option, just make sure you work with a lender that hasn't historically been known for randomly reducing or closing the line of credit.

Anywhere that you can buy property under market value, force appreciation, cash flow on rent, or use real estate to build wealth and reduce taxes is a good place to invest.

First, if you try marketing it pre-completion, with no customizability, you are reducing your buyer pool who wants to see it done which may drive your price down.

If I subtract vacancy cost (4 x $3,200), the net rent reduces to $19,200/Yr, or a 4.8%.

All else equal, the fans usually keep the tenants cooler without using A/C and they can reduce their costs.

If it's not been on market that long...they probably aren't ready to reduce that much. 

Personally, if she is otherwise a good tenant and has never caused me any trouble, I'd let her reduce her rent.