I have found a house that the owner seems to want to get off her hands.

I wasn't sure if that'd also apply to a cash-out refinance on a property that's already paid off?

And if they are found off-market and from relationships how do you forge them in the real estate investing buissnes?

Aloha Suzanne,  it think that its going to be difficult to find and on/off shore appointment setters who are willing to work on a commission basis. 

An expert like @Dave Foster could tell you if there’s anyway to pull it off if you have the extra 50% in cash laying around.

It's a myth promoted by ignorant "influencers" on social media.

Would there be rental expenses I could write off that would more than compensate for the marginal income?

Long term rates already have a .75 BPS to 100 BPS increase in margin spread do to risk, that will come off the table soon and lower rates just based off that and that would put my 30 year fixed rate in the 5.25% to 5.5% ish range. 

I'm 80% off market and would enjoy helping you anyway I can.

Plan is to reinvest most of the profits for 2-5 years before I quit my W2, go into real estate full-time, and live off the profits while continuing to invest.