Being quoted $1500 which seems high. 7.45% rate with 1 point charged. 

Because of material participation I can deduct that $350k vs other income.Using combined federal and state tax rate of 40% x $350k = $140k in immediate tax savings.

Hindsight is great, but why use a company with an F rating by the BBB? 

Now, we have the highest tax rate in the state but we don't have the best schools, amenities, or location. 

We will also birddog the best opportunities on the contracting side so i figure we can boost out hourly rate up to at least $100/hr (from 80), and jump from the build to contract jobs to take advantage (we have our own heavy equipment and dump truck).

HELOCs only make sense as short term funding - especially with rates where they are now. 

Personally I’ve never done the binder method and made a tenant multiple rent options, I’ve just set the new rate and sent it out to them via certified mail with a start date of the new rental amount 2 months out so they have time to move out if they want to.

But I'd take anyone's prediction on rental rates with a grain of salt and more than a dash of "show me".  

I had trouble finding a bank that would do two dwellings and ended up with a loan requiring 25% down and a few upfront points with 7.5-8% interest rate depending on lock in day.

Very low fees and probably equal or better rate - I have gotten 80K personal loans from SOFI.