I think all rookies should have to play for the league min. for at least 2 years, maybe 3. Players can receive small signing bonuses dependant on what round and if they are drafted, but the league would have to set either a max. sign bonus or set a predetermined amount based on round selection.
Doing this will force rookies to earn their keep and help them develope an appriciation for the priviledge of making alot of money for playing football. Could help the slow down the influx of punks in the league. A team would have the right to cut a player under these contracts without cap penalty too.
A $30 million signing bonus for someone who hasnt done anything professionally is a joke. A coorperation, law firm, or any other profession that could offer large signing bonuses to exceptional people straight out of college has a much better idea of what they are giving that much money to. These types of pros can demonstrate their skills vs an open field of competition includes the best of the best. College football is seeing skills vs other college football players....not pros. Tougher to gage.