Difficult. While I generally like things that move, I agree that some quickly get irritating. I would stay away from noises and flashing (i.e. non-constant) lights. I think Akula built a marvellous Zombie hunt board which I've seen at several shows now, and while it is a grand piece of work, whenever I looked at it, the blinking and flashing lights quickly irked me.
The smoke would be another no-go, unless you can get odourless paraffin. If you really need it for dramatic effect, maybe dry ice would be the better option (I mean, having a Cloud City table with the bottom covered in ACTUAL clouds would be quite the looker, but it would probably get irritating, too).
I think that for our purposes, it would be best to have them either "static" (as in a not-too-bright light, for example for reactors, and have others "at the ready" to switch them on to enhance the game (for example, flashing lights when the players trigger an alert, or a (covered, for gamer finger safety) computer fan which turns on just as the players enter the ventilation shaft.
The rest, like rotating windmills etc., I would leave to the railway modelling crowd. They "need" it because their interaction with the layout is limited, and in that context, it is less of an irritation than a pleasant distraction from the uniformity of trains going round in circles.
Finally, consider that any non-essential electrics/electronics in a house with small kids can spell trouble quickly (unless you have the little Vikings suitably conditioned already).