I see what you're getting at. Yes, I do have some ideas for keeping it focused. And yes I can always cut detail to "a bit of history and a bit of theory" to achieve that and yes I can refer to such things by linkage or reference - but I believe it is precisely by keeping an eye on the bigger picture of the basic design of such software in preparing the talk that I feel I can best make the pieces in the puzzle make sense for the selected audience level.