It’s about the same price as Vegas, perhaps a few percentage points higher per square foot.

I guess I’m confused as to the timeline of refinancing to ensure all boxes are checked before shooting myself in the foot.

Further, you avoid the potential of forgetting to refill it while tenants are away, having a single pipe freeze, and footing the bill for hydronic heat system busting open, flooding/ freezing the building (a not uncommon occurence). 

Your gf and child can come visit you there.

You will still need to get permits for that.BUT I caution you that you might not get the full price per sq. foot that you have in the main house. 

Putting your best foot forward is also important.

And two of those properties were for all-cash offers, which tends to skew the price-per-square-foot average down and implies that most of the people doing the buying in the area are other investors, not owner-occupants.  

They had a child together. 

If it's 4 units or less, they may use recently-sold properties as comps whose price-per-square-foot will be a bigger factor in valuing the property. 

Just throw a number out or by the foot or what?