^ *AGREES* And he looked ten when he was in the tube, not thirteen. Shaoran's drawn to look around 15/16 years old, there's too much of a difference between the little Shaorans and the older ones.
Plus, Real!Shaoran's sword can cut, and CCS!Shaoran's can't, it's said so in the first artbook as a comment to the cover of chapter 4 of volume 2 =D That he can carry that sword without a license cause it doesn't cut.
It'd be really lame for R!Shao to be the CCS, anyway- the only chara that seems to be the same as the original, is the Clow Reed that Yuuko knew, but that at least is cool and makes sense- how many cryptic, future-seeing, weirdo, mascot-making magicians can you have, really?
And if CCS!Shaoran had been kidnapped, do you think Sakura wouldn't have minded? She's even more powerful than Clow, she wouldn't just stand around and let FWR steal her boyfriend away.