I wouldn't call these things "peeves" exactly, as I'm not put out by them, but I do take note, or in some cases find them amusing.

One thing not mentioned in the poll, but often seen, is the wacky mixing of the various time periods of Highland Dress, and the mixing of the various modes of Highland Dress (military uniform, Day Dress, Evening Dress).

As for time periods, a person might be wearing an 18th century belted plaid and shirt but combine this with a diced Glengarry and diced half-hose (even worn without spats, showing part of the bare leg).

Mode-mixing might include bits of Evening and Day dress.

Most interesting are when both various historical periods and various modes of Highland Dress are ingeniously combined with bits of Native American and/or Viking dress, like a Prince Charlie worn with an 18th century belted plaid and Jacobite shirt and crudely knit bonnet, modern Day sporran, cream hose, and moccasins.