Montco my primary focus is the potential buyer or renter. 

From the date of the closing of your sale you have 45 days to identify your potential replacements and 180 days to close on one or more of those properties and complete the process.However, it sounds like this is your primary residence so it would not be eligible for 1031 treatment anyway.  1031 exchanges are only for investment property.  

Specifically, I have a friend who wants to buy this home as a primary residence, however the seller is not interested in FHA buyers and won't even consider offers contingent on FHA financing.

there is NO question that Californians lead the nation in out of state investments.with the primary driver SoCAL.. there is a reason MI has an office there..

I currently have 4 condos, 1 house, and my primary residence.  

There I met an investor that said he has his realtor license, but uses it more for investing than as his primary business.  

Not sure if that's the best strategy of if we eventually claim the home in PDX as primary residence down the road and turn our primary residence in California into a rental?

Make sure you get the Heloc while the unit is still your primary as that makes a huge difference for lenders.ask a few banks about their programs because they are NOT all the same.

If refinance is your primary exit strategy for a hard money deal, why not offer the Estate a shorter loan term?

Both were primary homes initially but the first one I rented out after I got married and was cashflow positive about $900/month in addition to the principal appreciation equivalent to a 54% IRR over those 5 years I owned the first property.