You have to do improvements that conform with the neighborhood.

as you prob know - 2018 conforming loan limits  increasing in King County are higher ...

A future buyer can use get as many supplemental loans as they want as long as it conforms to the original loan docs (less than 75% LTV, greater than a 1.25x DSCR).To your last point, relationships are important across the board.

I have a question re Freddie Mac and Fennie Mae Loans - Multi Family. or any other Conforming loans.I just had a chat to a mortgage broker who advised me that to Qualify for these loans the buyer must have minim equity equal or more to the loan amount.

However, if you're goal is to get the best rate and terms and you can qualify for a conforming Fannie/Freddie loan, I would have the property in my individual name.  

I had a unique situation where the property has two driveways (called non conforming) meaning the city wanted me to terminate one, and widen the other.

If it's not affixed and/or there's lot rent, chances are it cannot be financed (at least by conforming loan guidelines, maybe a niche lender will lend on it) and it'll narrow down your buyer pool or price. 

As a long time appraiser i can tell you that the answer depends on the experience and skill of the appraiser, the amount of research and support they did, and the the assumptions and givens of the assignment.An AVM like Zillow or your tax assessment is like the blue book value, a statistical analysis of hundreds or thousands of sales that may be fairly accurate is depending on how conforming your property is, clean the data is, and details of the algorithm (Taxes values in my area will be based on 2013 values until the next reassessment in 2020. 

You are probably going to want to conform to local standards, or at least have a firm understanding of what they are. 

You dictate what the property must conform to (cost, rehab cost, etc...), and if the property won't "play nice", you don't buy it.If you can't find any properties that will "play nice", then you're in the wrong micro-market.