crime and punishment

The only "crime" Candide is guilty of is being completely innocent and impressionable. He really doesn't know anything in the beginning, but this is by no fault of his own. He is like a child who must be taught the ways of the world. When a child gets curious and starts hitting people, its parents scold it because hitting people is wrong. They might decide to show it this wrongness by scolding in terms the child can better understand, like revoking certain privileges like television and sweets. Eventually, the kid will begin to understand that what was done was wrong. Candide has obviously either been brought up in some other, less effective way, or is just too stupid to learn this way.
The first punishment, the one that sets off every other painful experience Candide has, was being kicked out of the castle for going after Cunegonde. This action was arguably not wrong at all, just the product of young love, but it was deemed inappropriate by the king. If Candide had any sense at all, he would have made an effort to keep his affair a secret, but we know this is not the case. The king doesn't really realize how dumb Candide is, and isn't really in the wrong for kicking him out because anybody else would have known better. Candide doesn't really deserve this punishment because something less harsh might have actually taught him better to at least be more discreet in his pursuits of Cunegonde. It's not his fault that nobody ever taught him the ways of the world, but anyone who is still so ignorant by the time they reach that age can't expect anything less than harsh punishment and repulsion from society.