There seems to be information missing - why not get it from a traditional lender?

.🔴 Incomplete or disorganized documentation: Missing detailed plans, financial statements, or timelines could mean the borrower isn’t ready to execute the project successfully.🔴 Over-leveraged finances: Borrowers with excessive debt or insufficient personal capital invested in the deal could pose a greater risk of default.🔴 Questionable property comps: Overstated market values or inappropriate comparables may mean they’re inflating expectations.As always, thorough due diligence is your best protection.

The subtract off selling costs which will get you to near what you paid for the property (which will net you a small amount after paying off the loan and the missed payments).Before investing in next RE 1) get you finances in order 2) build up adequate reserves 3) learn to analyze the numbers better.  

I definitely don't make any money off the place, but the airbnb rentals pay for maintenance and my gas driving to and from WA :-) Question: Have any of you missed some either obvious or not so obvious red flags that would have caused you to negotiate or walk away from the deal and if so what were they?

It's certainly enough data to point you in the right direction.Otherwise, here's an article I published on the fastest growing economies in the nation, and many of these places are quite affordable and good places to start (Cincinnati, Columbus, Oklahoma City, etc).13 Real Estate Hot Spots You Won’t Want to Miss Next YearI hope my perspective helped.

New CPA time is a great time to reassess goals and opportunities and find out if you missed anything  

As Ian said, it's like missing the bus - if doesn't feel great, but another bus is coming.  

You miss out on appreciation on rents and property values if you sell and put the money into your current duplex.Hope this helps!

They miss to pay the small interest amount as of now.

You still missed the run up.