Not sure if that applies to all counties in the state or if it varies county to county.

Thoughts on these varied subjects?

Yes, you are right that lenders vary widely..

Returns vary by product, and 16% is not much of a stretch but 20%+ requires a bit more creativity. 

Net profit after all costs which should be the same as ARV Net profit after all costs is not the same as ARV.If you gave a $500k purchase and $250k rehab and sell for $1M, then your costs are $750k so 25% of that would be $187,500. 25% of ARV ($1M) would be $250k in profit and if by “all costs” you also mean to add in resale and holding costs, then this number would vary based on each rehabber and their specific holding costs which would not be a useful formula to use for all.Secondly, if you can find deals in this market with that kind of profit margin, especially 30%,  then you are one of the very very few or even the only one doing that consistently.

Your mileage may vary, however. 

Average cash flow (with zero leverage and self manage) is about $450.00 each (varies from $270 to $680).

So may vary a little. 

HELOCs for investment properties:The DTI percentage range varies by lender, and is less than what you will find for an owner occupied property, due to lender risk.

Contractor prices can vary wildly so make sure they are all bidding on the same scope of work and that the work you want them to do is inline with other properties in the area to get your ARV.PM if you need some references for lenders.