Yes, I put my sunglasses' earpieces inside of the helmet straps. The sunglasses seem more secure that way, which is worth it if both your face and the bridge of your nose are narrow. If I put the sunglasses' earpieces outside of the helmet straps, then forget to take off the sunglasses before taking off my helmet, the helmet's straps get tangled up in the sunglasses' earpieces, and the glasses are likely to hit the ground. I don't like that.
Skip the hydration system unless you're mountain biking? On my weekend long rides, I don't have a SAG wagon to bring me more bottles of water. There aren't stores right on my route where I can buy water, and it sticks in my craw to pay for bottled water, anyhow! I'd rather look like a rookie than collapse from dehydration any day.
It comes down to individual comfort levels, I guess. Some of us are more self-conscious than others. But I know that, when I get busy riding, I focus on the ride, and forget to worry about what I look like. Blessed oblivion!