A small startup should work as a team in a whole, so I don't believe that the developer should be a rockstar, but he or she needs to be very communicative and organized regarding to deadlines. It's very important to communicate the goals and strategies of the company, so the developer can make decisions in the technical side that are coherent with it. The team should create enough non-technical artifacts, as wireframes, screen mocks, functional test cases, etc so it's clear.
As Michael Gerber say in the E-Myth Revisited, in a company we have 3 types of people: The entrepreneur, that looks to the future and drive the boat; The manager, who looks what worked in the past and how to maintain it still working so the boat keeps moving; The technician, that knows the details of the boat and have the specific knowledge to operate it. In a startup your first developer needs to fulfill this 3 roles in TI if no one else can.
Ideally, a startup developer needs to be a rockstar. This means they need to be able to be self-sufficient in many ways, since budgets (fiscal and otherwise) are extremely tight. They need to be able to set priorities and communicate changes quickly and efficiently.
That said, once a development team reaches a certain point (in my experience 3-5), it needs a decision maker to move forward in times of need. This technical lead usually will take the role of CTO, but doesn't necessarily need to. A Chief Product Officer (a lead Product Manager) can often fill this need temporarily, but will be leaving a large gap unfilled on the technical side.
If you're not technical and are hiring outside help, hire help that offers this leadership for you. An interim CTO or project manager on the consulting side can definitely help things stay on track. Note that the more layers of communication you add will definitely slow things down and add some confusion.