Could an App still talk to the hardware as you state in number 2 with both of my points in mind? And wouldn't the App be a hybrid instead of what you state in number 3?
It could be possible although I doubt it would work with any of the OSs that we have already. They are not ready for two softwares (be it OS, APPS or whatever) to talk to hardware directly.
That would be a real mess :S
Besides, there's no point in having two OSs running at the same time (if your apps is talking to the hardware it is becoming and OS!!!!).
Also would another special case be gaming online? Or a 3rd world or 2nd world country where people can not afford the luxuries that we have but could use at least a semi OS that could connect any hardware to the Internet?
This already exists: linux does all that (or freebsd...)