I was fortunate enough to fly in Hawaii for 7 years, did not even own a pair of shoes for 5 of them. I flew barefoot for the whole time...it does make you a better pilot, it teaches you to be gentle on the pedals, otherwise it hurts. Most people apply a few pounds of pressure to each of the pedals and then push more with one to apply it. When flying barefoot, you dont apply any pressure unless needed, hence you fly smoother.
As for the smell---non.....the only reason your feet smell is because they are stuck sweating inside socks and shoes. It did take me a year to get my soles back to a "normal" color after I returned to the mainland though.....
