Here's a bit more in detail about how rates are calculated for DSCR loans:1.

Others may disagree, but I would highly recommend paying off all of our debt and increasing your savings rate before investing. 

It requires the borrower has significant experience and is very costly (in terms of rates/origination)It's generally really risky to do 100% financing especially if you are inexperienced.

Is it Cash Flow, Cap Rate, COC, all three or something else?  

At a glance, it's just Quicken 2.0: advertise a great rate, bury in the small print over $10k in junk fees per $600k borrowed.

Essentially I am finding and procuring the land/lot via traditional financing and funding everything through the development phase until we get to Construction Loan. 

Here is what is being considered:SCENARIO 1):1) Parents loan us money at X% rate.2) Loan terms would allow for early payment without penalty (we would get a conventional loan in 2-5 years to pay parents back).

Then make sure you have enough in reserves because it would be a reimbursement draw for rehab funds.

@Imdhadur RahmanBest I’ve seen is 15% down, and you pay more in rate as a result of the down payment.

In these cases, interest rates tend to surpass cap rates, compounded by rapid appreciation.