My main concern is the limited cash I have available for the down payment and renovation costs.

My strategy would also be going for more price appreciation than cash flow. 

Always have a cash reserve on hand, maybe twice what you think you'll need.  

We learned how important it is to rebalance tests, which is something that is often missed but is essential for long-term success.

Regardless of your FICO, you will need cash money to be able to invest in holdable real estate.  

Saying that, we are only interested in buy-and-hold investments that offer positive cash flow upon purchase and some minor non-structural reno's. 

In 3 years I’ve doubled my investment through sweat equity, and when I reached 10 doors I was able to retire my parents with the cash flow.

If it doesn’t cash flow in this scenario then it was a bad deal to begin with.

Getting those properties for pennies on the dollar, renovating them so they can withstand another 100 years, and fully furnishing them at a 30 day minimum is giving off some solid cash flow!

The rates for a purchase money loan (one where you take the loan out to directly acquire the property) vs when you do a "cash out refinance", which your loan would be if you chose to pay off the line with a loan on the primary residence, it typically done at a higher rate.