Training abds does not mean to have abds, but to be in good shape, you will never see someone who has very good abds and be sick, but you can have 20 inches arms and be sick. ABDS IS THE BAROMETER OF YOUR BODY.
yes but inside the layer of muscle..thats when it can function as the barometer of your body

..not the muscle itself.
also....the above comment you mentioned doesnt change the fact that you dont need to do abs daily to have good abs. what you need is low fat % and to work abs 2 times a week (with weights or without)...
but certainly not 100 or 1000 reps daily.
abs 2 (maybe once..or max 3 times) times a week: 2-3 sets of abs 8-20 reps....
in other words..treat it more like other muscle groups.
maybe if you train for some kind of sport where you need alot of muscle endurance...more reps can be useful.