I literally just saw the video before you posted it. It gave me a much needed insight on how the gameplay works and I'm willing to try and learn. You know, having played the Final Mix version that came with 2.5 HD, and after beating the Cave of Remembrance (no luck with those insane Organization XIII superbosses, though), I knew that there was more to the game than just the basic "Mash X, hit Triangle sometimes, and Cure", but the combos shown on the video just blew my mind. I didn't know they were possible at all! And he explains it very well: I never really needed them during the game. I didn't even know how to use the limits or how to level up the Drive forms until halfway through the game, because I never felt the need to really use them. The game felt really easy.
This is a great video. I just beat KH2 this month, but I think I'm going to give it another go to try and use these strategies.