Also, with potential inflation increasing from money injected into circulation and mortgage rates currently at all time lows paying down principal is objectively one of the least efficient uses of your capital?

To do a construction deal like this, you'll be need at least a 30% equity injection, especially if it' a first time.

If our portfolio is large enough (mainly b & c class property), would it possible to bring in a Private Equity Firm to take partial ownership in the LLC while injecting capital and restructuring the firm?

I don't see much value that can be injected into the kitchens. 

As noted in prior posts, the key is that everything is done by and for the plan, with limited interaction from you and no injection of personal capital. 

.), cash recalls and shares dilution in case the property needs cash injections, etc.

Our current financial situation would enable us to start investing now with $50k in cash, and inject an additional $50k in cash each year from our full time jobs/incomes.

How much a month can you afford to inject out of pocket into the property to carry it while holding for appreciation.

We are probably reaching a point where we will have to inject more money into the business, but it has been a good run so far.

When it comes to purchasing a “value add” project you can expect to pay 8 – 10,000 less per door than these figures (give or take) and then inject approximately 3- 5000 of capital per door thus having the remainder for your profit.