My younger brother is 16 and his biceps are around 16-17 inches in length. Is that bad?
16 is a fine age to start serious weight training. Anyway, the length of a muscle doesn't determine its strength really; what is more important is the cross sectional area of the muscle.
I had to skip out on conditioning to finish my math homework. I went for Arnis though. This class is turning out to be really awesome. Worked up a good sweat doing combo drills and we learned about brace blocking and counter-striking. Going back for Muay Thai later.
I'm a black belt in karate and I put protein powder in my smoothies everyday. Does that count?
Protein powder isn't some magic substance; it's just protein. You need to eat a complete balanced diet for your needs for it to be of any effect.