An LLC won't provide much liability protection if the business is not established and run correctly.  

I know this is a old post, just curious if there was a note investor group established in the Puget Sound area?

The risk is taken when: (1) the customer has established a history of proven past success and (2) that the new project is undertaken with the proper due diligence and careful considerations that made the past successes possible.  

To protect your assets in order of importance1) Follow the law and do what is right2) Be respectful of everyone and when something goes wrong fix it immediately3) Have good insurance4) have an LLCThe first three are a must.

I wouldn't do any figuring until I had established  that number.

How respectfully do they enter and tour the unit?

It's seems like you may have established some sort of rapport with them, I think it's highly unlikely that they will call the loan due and if they do I'm sure you'll be able to come to an agreement. 

If you get a duplex, get the best renter possible, and pay your rent just as you were, paying yourself, and letting the tenant pay your mortgage/utilities.Now you own a property, you have established a relationship with the bank ... and you have your first "deal" under your belt... 

I don't know the area, but 8%,8%, and 10% of monthly rents respectively is a decent guess.  

Is it in an established neighborhood or rural?