Wizards also have better skills than Sorcerers, courtesy of high Intelligence. I think some feats are a good idea for any class, for the sake of customization. (Basically advocating more feats for everyone and less class features; class features becoming generic feats that people can take with appropriate prerequisites.)
To encourage metamagic and item creation feats, Wizard bonus feats are essential. And I don't think these feats make someone substantially more powerful, so I think the Wizard remains fairly balanced vs. not having the feats. It just adds some more flavor. On the subject of item creation feats ... blech, way too many ... make it two or three: potions/scrolls (one shot items), charged items, permanent items. Or maybe not even that. I don't really see the need for item creation feats.
So balance-wise, I think the Wizard feats help improve Wizard a little, but not hugely, and Sorcerer is very good in combat, so closer to Sorcerer if you give Wizard some extra feats.
Just my thoughts ...