Everything you fear could potentially happen, and there's no way to guarantee it won't happen unless you never create a class of preferred shares, always own a

Everything you fear could potentially happen, and there's no way to guarantee it won't happen unless you never create a class of preferred shares, always own a majority of the stock, and always control the board of directors. The future's just too unpredictable for anything you do now to somehow contractually protect you from every bad outcome. Some of the things you're afraid of, like not being able to sell your shares without board approval, are standard operating procedure at venture-funded startups. If I were you, I'd talk openly about my fears with my other potential cofounders and the parent company, listen carefully to what they say, and then go with my gut. That's about the best you can do here.