mariner: Minhag ha-ir defiantly plays a role in tsnius. There are many poskim that discuss this. The socks vs no socks minhag in most communities it is considered un-tznius to go without socks. However in certain communities even the families of rabbonim go sock-less and it is acceptable to do so- if you live in such a community. The nuances of tznius are not hard stone halacha but what is considered accepted in that city/community.