The basement is full, concrete walls that are very straight.  

I have a few friends in the area that have moved houses and none of them would recommend the individual or company hired.  

If they are, then the enemy method works.

There really isn't enough information here for someone to give you a proper answer.What you need to do is calculate those tax savings over the next 5-7 years (or however long you plan to stay in the house) vs. what the interest rate reduction will save you over that time period.

Since I invest from abroad and visit the U.S every few months, I need a course that covers the multi-family investment process in detail and offers a strong community for support and collaboration if needed.Any recommendations would be greatly appreciated!

You are buying a primary residence so should be able to take advantage of an FHA backed loan.

That should help significantly.

Secondly I would look into if it make sense using realtor or not, there are markets that it makes sense and there are markets where unless you as the owner are paying agent fee most will pass. 

In that case the rental contract spells out specifically the obligations of both parties.What I personally do with all my rentals is that I regard the rental agreement as a contract that both parties are obligated to fulfill.  

I see you are in Seattle, James Dainard Cohost of the Bigger Pockets On the Market Podcast does local events and meetups.