I would use the cash flow for future capital or for paying down the principal. 

We can always cash-out refinance in the future, but will probably only do that for our primary residence (which is on schedule to be paid off in ~10 years).Without looking at your numbers, it sounds like you still need even more cash flow, either (a) through refinancing - such as your current plan to refinance  combined with buying more properties, or (b) you need to adjust your current living standard.

The important thing is to learn what went wrong and use that knowledge to ensure a bright future.

I realize that the site says "In the future, we will expand in adjacent markets like multifamily acquisition and renovation, and non-bank new construction, which will greatly expand the market size addressed by Groundfloor."

They may not.They will be required to fill out a CTR (currency transfer report) as it is over $10,000. 

Proximity to jobs is the #1 reason that people live in this area, and will continue to do so for the foreseeable future. 

I will reserve my opinion on your future.

We are predicted to have strong future increases in population.

Build it on excel is the best bet... you can adjust it for use in the future

If you want safer investments, you give up a greater potential reward.Betting on appreciation in the future is a lot riskier than analyzing current cash flow and making an investment based on that, but it could end up with a much greater return as your family friend noticed.It all comes down to what is your risk tolerance, and what are your goals.