I am currently retired and just purchased my 1st duplex in Upstate NY using a conventional investment property loan. 

But if all you're doing is acting as a PM, that's all I'm willing to pay you for.No conventional lender is going to allow you to have a CLTV (combined LTV) of 100%.  

Best value at selling is to remove the JADU due to poor auction the result of mostly needing a house hacker   In addition, if you already have a regularSDU (which would be primary reason to add JADU over an ADU), the property by rule does not qualify for conventional financing.  

The loan I have right now is the loan from the bank - a conventional loan.

You can move to one of these markets and do a 3.5% down FHA loan, live in the property for a year, and then get another 5% down conventional.

Anyone aware of the ins and outs of how Fannie Mae-backed conventional lenders count income from Airbnbs?

A friend in lending told me I'd get better pricing if I have private lender do a $630K loan, record a deed of trust, before I close and then get a conventional loan after to refi the existing debt.

First off a 10 Unit is commercial not conventional so the qualification requirements are higher and you need to understand the loan parameters.

Good value in Chula Vista especially with the new Billion dollar convention center going in.

Yes, the lenders looked at my DTI and I was able to do the first 3 cash outs with conventional loans.