My only -minor- issues would be that I can barely make out the source up until the 2nd half of her theme starts up (When the chords kick in after the voice sample) - also, the synth used during that period seemed to swell to a rather high pitch when you were holding the chords - as opposed the staccato which complimented the rhythm a bit more. No, I'm not saying the main Sakura melody should be playing ALL throughout, but perhaps you could HINT towards it by playing the first 6 notes and letting it echo/fade after the last note; like a teaser y'know?
As for the more technical aspects - I'll let one of your fellow professionals tackle that haha.
Overall, I found it really enjoyable man. I know this is a remix OF a remix in a sense, but so far it feels like everything's working together nicely.