This eliminates exposure of assets in the trust to your personal liability.

Have you modeled out your returns (and will they be in excess of 9%)?

The unfortunate thing here is that investment properties foreclose at a higher rate than primary homes so many banks just don't want the exposure to this.

Are you paying additional rent which is being contributed to your down payment at the time you exercise your option, and if you do not exercise your option, will those excess rental payments be refunded?

I don't invest where there is rent control or excessive HOA oversite. 

There were a few reasons why I chose to refinance instead of using a HELOC.1) I couldn't afford exposure to variable interest rates, knowing that I would not be in a position to pay off the loan for many years.2) There was no point in having a line of credit, since my goal was to keep the borrowed capital working for 30 years, not pay it down early. 3) A refi on a primary residence is a lot cheaper than a HELOC, in the long run.Like you, I was dismayed when I came to the realization that the cashflow would be close to zero, since both the debt and equity for the rentals would be borrowed (100% leverage).

I have purchased a property in cash and am considering pulling in a partner to limit my exposure.

If I became concerned about my exposure I'd buy an umbrella policy.

As long as you're self employed and have the excess income that you do not need now, I would recommend a Solo 401K with both regular and roth accounts. 

Volunteer with Habitat for humanity projects (or similar non-profit rehab programs) and get as much exposure in the community as possible.