It works now, for some reason my address was acting up. Time to read.
Edit: Actually you messed up somewhere. When you said that Xehanort was absorbed into Kingdom Hearts. Riku actually managed to gain control of his body. When Riku did that, Xehanort's heartless was still in his heart somewhere. That is why Riku had the form of Xehanort in Kingdom Hearts 2. He took this form when he excepted Xehanort's darkness. So Xehanort's heartless could not of been inside of Kingdom Hearts. The Kingdom Hearts we saw in the first game was not really Kingdom Hearts. It was the door to darkness. The real Kingdom Hearts was revealed in Kingdom Hearts 2. When Ansem found Xehanort he did not have any memories. That was before the heartless and nobodies existed. It was also before Xehanort casted off his body and soul to create Xemnas. It was before Xehanort even became a heartless.