I have one big problem with paladins. Not everyone they fight is of evil alignment, they're just doing something evil whether they know it or not. And since smite evil is one of the paladin's main abilities and they're limited in its uses, it really stinks to hit an opponent with a smite just to have the DM tell you "Sorry, he's not actually evil."
I propose one or both of the following fixes:
1. Make the detect evil ability a quickened instead of a standard action so that the paladin doesn't have to waste a round to find out if an enemy really is evil.
2. Have the smite discharge ONLY against an evil creature. His weapon might glow with holy energy, but unless he hits an evil creature it won't discharge, and if he wants he can dismiss the charge from his weapon to be used at a later time.