I think that unless your scope has variable magnification down to x1, using a laser or weapon light is counter to common sense. By all means, if you have a x1-4 scope that's designed to do short to medium range well, lights and lasers are short range. Trying to do room-to-room with a x3-9 scope is like reading a newspaper with binoculars.
Of course, there are exceptions. Swing-away scope mounts are one solution, I don't know how well they keep zero, but they exist so someone must use them.
You might find a trespasser on your property in the night and want to let them know you've got a gun on them at more than arms length, a x3-9 with a light would do that, though you'd need a prohibitively large light to actually throw useful light at that range (I'm thinking of my TK21, at 2x CR123A with a bulbous reflector housing, it's not terrible, but not something I want on the end of my rifle).
You might be moving at night and want a weapon light as opposed to holding a separate light and sacrificing readiness, but that light becomes ballast when you're looking through the scope.
I'm just trying to figure out circumstances, I only shoot at the ranges here in Jerseystan so my "weapon" lights only help me find brass at closing time.
I'm not familiar with "no-scoping", but I'm about to Google it.
In other news, this. To me, it seems to just be a pistol that someone forgot to stop scaling up. Or, just a way to get .50BMG energy out of 16" of barrel.
http://www.thefirearmblog.com/blog/2011 ... dinosaurs/