I understand that we would have to smooth out a lot of details in a partnership agreement and run numbers to see if it's feasible, but I am trying to think of ways to creatively dip my toes into the water. 

If that's not feasible, the markets mentioned here are great and of course, I have to throw Austin, TX into the mix.

If you are going to be doing this for a long time, it makes sense IF an STR is feasible.

I totally get that someone may hear that and say it's absurd to give away 15%, but my W2 job is still my main focus, and having a PM makes it feasible for me to keep my focus where it needs to be, and allows me to scale easier should I want to.  

@Ash Patel@Matthew PaulThanks guys, Im also going to consider getting a storage consultant out to do a market feasibility study for me. 

I would recommend doing the Addition as you mentioned (adding more bed, bath to the main house) and then adding a ADU if that is feasible.

Is freelance a feasible way of starting out as a TC?

Yes, the tax questions I asked in the original post.Several reasons including:  1) It will take me several months to get plans, bids, permits.  2) It's in a high snow area, not really feasible to start until spring. 

We started our feasibility period last week. 

I would generally recommend starting where you live but understandably for some, that may not be feasible for various reasons.