I can only second strongly the point that the belt keepers on the back of the Kilt are sporran straps, at a recent games, I saw a sad case of a torn kilt, as a result of putting the belt through those loops!

I do wear a belt, but onlt because I think the kilt looks incomplete without it. But only when I'n not wearing a waistcoat. It is, however tottaly a natter personal taste