Read inherited leases thoroughly before the interviews, make a table of all important dates for each unit, like all renewal dates, how many days in lease for notices (inspections, non-renewal, etc.), and any special terms in there like required to maintain minimum heat, etc. 

My only consolation is those that lost out because they were waiting for others to lose everything so they could profit.

Has anybody structured GP/LP like this and thoughts on waterfall table and cash flow distributions?

They can come to the table with cash to make up the difference.

We do have 4 other properties we rent with significant equity so using equity from one of those is on the table as well.

As a real estate agent, and having dealt with these companies, you could end up leaving a lot of money on the table.

Since you bought this for $5k less than the appraised value, I don't think there would be a big enough jump in adding value where you can do a cash-out refinance, and you would likely be bringing money to the table to pay off the HELOC with a standard refinance. 

I think you might end up leaving quite a bit of money on the table.

If you're looking to do a fix and flip - you'll need to come to the table with at least 10% towards the purchase price + closing costs.

(IRS provides tables to calculate the amount(s) based on your life expectancy each year.)