It sounds like you've absorbed a bunch of problems already and a new sewer line and the current basement situation will cost you way less than the $50K in fees to sell it. 

BF it, live in it, then leave it!

We found an opportunity to purchase a huge SFR with two kitchens located next to a commercial zone which was previously used as a sober living facility.

Most everyone mentioned the weather and appreciation due to the weather making it so desirable to live there. 

Quote from @Chris Hertig: We recently purchased a multi-family property and have someone living illegally in an uninhabitable, detached garage. 

However, what I don't know is how long have you been in your home (how much equity do you have in the home) and what is your current interest rate.  

My wife and I have 22 residential assisted living homes in Colorado and three commercial senior living communities in Colorado and Arizona. 

As a beginner investor based in the Seattle metro area, I'm eager to learn from your experiences and share my journey as I get started in this field.My current strategy is to focus on live-and-flip for the first three deals (looking for my second deal) to gain hands-on experience while building equity and learning the ins and outs of renovation and the local market. 

Quote from @Devin James: Im currently learning this lesson with New Builds that have taken twice as long to complete than anticipated.....Finishing a Real Estate project ASAP is critical because...1) Holding Costs add up quickly- Loan Interest- Property Taxes- Insurance2) Investor Capital- Our financial projections are dependent on how fast we can turn our investors capital.

Your answer needs to make sense, and be true.Also refi'ing your current primary into an investment loan also has the potential to be fraudulent if your family still occupies it as their primary.