He starts out at 1600. What if he could beef his rating quickly (to a point) by playing the AI at selective levels with cheats disabled? There would be a limit to the amount he could raise it to, such as 1750 or something. Obviously, you shouldn't be able to become a top rated player agianst only the AI. The game would add or deduct triple points.
For another idea, maybe there could be one initial game against the AI (you could not pick the map or the civ for the AI) in a no lose situation. It would be a one time deal that could not be repeated without creating a new acount. You would select either the Hard or Titan difficulty. If you beat it at Hard, you would start with a 1650 which could beaten back down if it wasn't legitimate (1620 if you last 35 minutes). If you beat it at Titan, you would start at 1700 (1650 if you last 35 minutes). You could maybe even opt to take on two Titans and start with a 1750 (1700 if you last 35 minutes).
Even a 1750 (which you would have to beat 2V1 Titan wihtout cheats enabled to get) would not make you a top rated player. It would just keep you from having to stomp Newbies, which could be considered a waste of time for you and them. Of course, this is all asssuming that you are not intentionally "smurfing", which I would like to believe is the case with a lot of new accounts.