1) There's ranged armor?! What's that? I thought you wear it.
2)Best if LeeAnn answered this.
3)I don't see why not.
4)Most likely not. LeeAnn can give her input, but i'd guess not. Simply because most requips are a weapon and an armor. It's not like you'd have to requip every piece individually.
5)ReQuip wold be in a category like Metal. Or maybe No-Element.