Problem with the width thing, I can barely manage to keep an 8.5 D from flopping around, so never mind anything wider than a D. Besides, in the US, I think the widest I've seen is EEE. Even my friend with the size 16 feet wears a medium. He goes barefoot a lot too, but since we can never be barefoot long enough to noticeably widen our feet, we must stick with medium width. As for dress shoes, yes, I have some with "windows" in them too, dress sandals. Basically, I never wear a shoe without a heel except when exercising, I'm either barefoot or in zero drop shoes.
Rub your feet with extra virgin coconut oil before putting your socks on. It will make your feet smell better and it will kill any bacteria or fungus between your toes.