It is standard to reserve a portion for the team. Right now it is just @themarkymark but that may change down the road.

@steemstem as far I can see is more focused on Science, the idea I had was to support the entire breadth of STEM and have a place to talk about Technology as much as Science. Where talking about computer building, Raspberry Pi hacking, development all fits equally. I wanted a fairly wide niche but not a general-purpose community like Pal/Neoxian.

As for what will be done, I haven't gotten that far. I have no idea if there will be much sold at all. If there is, I will start thinking that far. As far as onboarding, my initial thought is I don't even need stemgeeks.net because @steempeak is so much better, but I felt it would be used by experienced users and having a dedicated stemgeeks.net is a much better vehicle for onboarding. So it is something I am thinking about.