Steel is strong and resistant to damage/decay (assuming that it's actually stainless steel he turns things into which follows since the city is silver and not rust red)....but to a lesser degree than Steelheart himself is...not sure about his other gifts. He also can't gift it to living things (assuming the steel transference ability is gifting), only inanimate objects (that people then can use). Prof also can't gift to people directly but rather to object that they can use. Same for Conflux. It seems like they are able to (to use a cosmere term) invest into non-living objects.
Back to Steelheart and his gifts, he can't fly rather he controls the wind which lifts him. Kind of odd that he would end up making a city known as "The Windy City" his home. Perhaps he did gift the ability to parts of the city, but we don't recognise it as no one is aware? I can't recall, but did the wind do anything odd apart from Steelheart in either Steelheart or Mitosis? Just spitballing here, but I am starting to also think that ALL epics gift their power in some way.