ChristiaanJ
From a Cabin Crews view its nice to see someone is interested in the safety demo for genuine reasons.
However I think extended demos would be a waste of time as many pax are to up themselves to take notice.
With regard to the doors manual or armed, honestly you would not need to know, if an evacutaion was ordered the doors would be correctly positioned ready.
Back to the point of exit seats. During boarding we as C.Crew pay close attention as to who sits in the seats, as they are restricted (CAA, not sure about FAA regs). Basically ONLY fully able bodied pax may sit in these seats. Also when in a exit seat the pax are briefed on exits (again a/c types regulations ect come into account) must pay attention to their briefing. If the pax wether positioning crew, frequent flyer or regular pax does not wish to pay attention they will be moved.