Wearing a crown?

Well said. I don't think looking like stage performers or wandering lunatics actually enhances social skills, regardless of the quality of the crown on one's head.

Items of Quality are easy to abuse when they're allowed to extend beyond explicit tools. I prefer a conservative approach, if only to prevent Magi from dressing up like a circus just to get bonuses.

Indeed - though that said, as I have said above, bejeweled clothing is a social tool and getting rid of that possibility cuts off a fair bit of utility from IoQs.

A crown with a pointy hat through the middle of it might be used to denote a senior magus?