How much overweight is TOO much overweight? How far outside the w/b graph is TOO far? This is what bothers me most about loading outside the limits. Our performance graphs don't provide this information because if they did the graphs and limits would be different. Ofcourse there's a certain safety margin which is just that, a safety margin. If you don't know the exact weight and it happens to be 100 lbs more than you think, is it going to kill you? Probably not, but calculating with 100 lbs overweight and then actually having 200 may put you in a dire situation.
Stick to the books.
As for training overweight. My god, what are we teaching people...
Perhaps 3 inches of ice on the wings is ok too.
What about 3 quarts of oil?
How high above the 1500 foot ceiling can you go before it becomes dangerous?
How about that TFR? Is 10 miles into it OK?
A 300 m grass runway, will it be enough for takeoff on a 35degC day at 5000 feet in a C150 at 100 lbs over gross?
If we don't use ALL the limits as limits all the time, how do you know which ones are OK to break, and when?