I'm playing a halfling wizard at the moment, and that made me realize that wizards are the ONLY class that cannot use a sling without expending a feat, but they can still use a crossbow (!?)
One may argue that using a sling in a efficient manner might not be easy, but neither is a crossbow. I mean, slings are one of the most primitive and simplest ranged weapons, and it's kinda weird to not be able to use one as a wizard (specially a halfling wizard, every halfling should have a sling, is almost like hin-law)