For employment based green cards (EBx) the applicant may use his/her EAD to work in a job that is similar to the petitioners I140 case (this is known as AC21). I can't go from Design Engineer on my H1B to CEO on my EAD :(

Set your title as Chief Design Engineer on your incorporation documents. In practice, no one will probably bother to check, and even if they do, they'll go by what the title is on paper. The reality is, you'll be doing mostly programming work in your company and you have EAD, so you're set. This sounds like a good setup from how understand it, but double check with an attorney. If you need referral to a good immigration attorney, drop me a line.

Right, of course; in my case, I've got an EAD through my wife's company, so I've probably got more latitude than yourself.