Instead, I have established a donor advised fund (DAF) for charitable giving during and after my death. 

Doesn't seem like the FED has much control this time around considering the 10Y T bill (and 5Y) continues to march higher even with the FED fund rate dropping.

And a little skepticism that the market would continue to grow at 5% or more on average (it's been ~7% average for the 8 years I've lived here)@Dave Foster I filled out the BP spreadsheet here for the sell or rent decision, and similar to you advice, selling and investing the profits in index funds performs only slightly below being a DIY landlord, making that seem an attractive option. 

Does it make sense to use your HELOC or borrow from your retirement funds to purchase a high risk property?

Buyer can’t make you sell if you don’t have the funds needed to close.

Just recently completed a cash out refinance to free up funds for my next investment.

The funds would be better purposed on more turnkey real estate, but good luck.

Also what percent is the funding fee, 3.5?

Carrying costs in purchase and or rehab is financed, cost of capital on refi, re-recording, title, updated insurance, etc. their are many costs at play after initial funding then to transition long term unless your straight cash on the front end.

I guess the purpose for this is to help fund community improvements and maintenance though it's a bit unusual since HOA fees and property taxes typically cover these.