In our experience, the #1 mistake landlords make when selecting a Property Management Company (PMC) is ASSUMING instead of CONFIRMING.

I feel like I have an advantage here by being in a house with so much equity but I'm not sure what to do.

Cash-out refinance pros: interest rates tend to be lower than HELOCS, you have the flexibility to do whatever you want with the proceeds, interest from the mortgage may be a tax deduction, and there are multiple types of loan products and structures to select from. 

I was thinking about a way to take advantage of this and pay off a house at an early age.

You will have the perk of taking advantage of the appreciation and since you already know the area you don't need to get to know a new area.

While finding a deal that works without the house hack would be great, you also have an advantage in that you will either be paying rent to someone else or to your self.  

It's also possible the contractor says they are following "green methods" but are doing the same old thing and taking advantage of you.

I took advantage of the no capital gains tax period and will put the equity into investment projects closer to home here in Maine.

It is treated as if it went directly into your pocket.You get no tax advantages or disadvantages.

I took advantage of the no capital gains tax period and will put the equity into investment projects closer to home here in Maine.