Unfortunately this is a investment in oneself.

I'm attempting my first renovating buy-and-hold, I'd like one solid flip a year (I know, just one??), self

Being able to be honest with oneself is a big component of it.

I believe to send yellow letters can get results and a UPS letter could distinguish from the rest because it is more personalized.

Thirdly, in the future I would use possibly an expanded name, like David Roethlinsberger Roberts, to distinguish your self from other David Roberts. 

The IDFPR may “refuse to issue or renew a license, may place on probation, suspend, or revoke any license, reprimand, or take any other disciplinary or non-disciplinary action as the Department may deem proper or impose a fine not to exceed $25,000 upon any licensee under this Act . . . for any one or combination of” the grounds for discipline set forth in §20-20 of the Act, 225 ILCS 454/20-20.Additionally, a licensee may be subject to both civil penalties and criminal liability for the unlicensed practice of real estate brokerage: Any person who practices, offers to practice, attempts to practice, or holds oneself out to practice as a real estate broker, real estate salesperson, or leasing agent without being licensed under this Act shall, in addition to any other penalty provided by law, pay a civil penalty to the Department in an amount not to exceed $25,000 for each offense as determined by the Department. 225 ILCS 454/20-10(a).     

You need to find your competition, and figure out how to distinguish yourself from competitors.I would argue that's all actually the first step.

But I love the hypotheticals about how to protect oneself in this scenario. 20% non-refundable EM, working as planned until closing (she is NOT a cash buyer, so there's that), etc.

I think investor friendly agents are willing to submit low bids with a straight face, show you "pocket" deals that come through their agency, give you background on areas you don't know and estimates on rents (although one needs to do more research for oneself).

We’ve been full-time investing for 6 years and always looking for ways to distinguish ourselves online!