Before I invest in furnishing the unit I was curious about how much demand there is for mid-term rentals in south Denver.

Financing Strategies – I’d like to put 15%–20% down—what’s the best way to secure a loan with manageable terms?

What this CEO was referring to is the government’s support of housing through the GSEs, which provide very good loan terms for multifamily owners, and his statement was that this is a good source of takeout financing for their borrowers.  

I've been searching through northern Calfornia STR markets and a bunch caught my eye, but everytime I dig deeper, there's some problem like regulation or profitability. It seems like Southern California does not have ...

Be clear on terms—percentage of equity, profit-sharing, and exit strategy.

We realized the data indicated there was a gap in short term rental housing in the 1 bed 1 bath category.

Don't let your loan box you in2.

I agree with @Collin Hays especially in a state like NJ that is very one sided in terms of landlord/tenant situations.

So we would have to get a loan, pay off the seller and transfer title and then wait the seasoning period before doing a refi unless there is a bank out there that will treat it as a refi off the bat

Unless the loan is a much better rate than the HELOC, which it probably won't be, then keep the HELOC and don't pay the origination fee on a second mortgage.