like I don't think Remus has any trouble with silver, at least, not in human form, but I'd love JKR to confirm that

Ditto. It seems to me that in Rowling's universe silver doesn't hurt werewolves as Remus deals with silver items in OotP. I tried to research the origins of the concept and found out that it is based on the Christian belief that silver is an ultra-pure element and therefore able to destroy a dark creature like a werewolf. Since I consider the wizarding world as not rooted in Christianity (for no particular reason, only because it makes more sense to be rooted in ancient paganism), I decided to ignore the whole silver-hurts-werewolves thing.