However, it is almost impossible to say since not only economic indicators affect the economy, but also the expectations of the market. 

It would be impossible to account for nearly enough capital improvements to cover the roughly $370k in appreciation from the purchase in 1994 to the sale in 2017. 

I figure if anyone knows how to make something like this happen (or deem it impossible for once and for all) it would be this crowd. 

Depending on the lot size, it may simply be impossible to add a bedroom to the house. 

Unless you have assets to borrow against your goal of 5 houses in 2017 is impossible. 

If obtaining 30 houses in 5 years seems impossible, does it seem possible to get 5 in year one, then 10 in year 2 and 15 in year 3?  

Bad news is that its next to impossible to get passive income on properties in the areas of Seattle you're looking at without substantial down payments.

The MFU, even 2-4s, have the necessity of sharing a common boiler and thus it's impossible to have ALL utilities separately metered.The generalization would be that all Oil based heating systems will present this same problem.Use of LPG or Propane might be solvable with separate meters per unit, but you need to investigate further.

One of the problems you run into when you buy any property out of state (or Country in your case) is the logistics make it impossible to guarantee you aren't going to walk into something that wasn't sold to you.  

I still want to keep my day job it's my passion however, it is next to impossible to be in that business and not work for an employer.