is where i don't agree with you, if you take a look, this was confirmed a while back Sora gained the ability to wield the Keyblade when he reached out his heart to Ventus after sensing Ventus's shattered heart. By joining his heart with Ventus's he gained the ability to wield his own Keyblade, as well as Ventus's. he doesn't need ven's heart to wield the keyblade, but he would need ven's heart to wield 2, as shown in kh2, and if you remember, COM and the very beginning of days happened, in the beginning Roxas is shown using the keyblade (vens keyblade because he has vens heart) now at the beginning of days, COM is still going on, thus why roxas was asleep for a couple weeks, these instances prove that Sora has his own keyblade other than ven's
