Alright, here we go...
If you're going to go with sequenced piano (which is extremely hard to pull off well) you really need to make it sound like it's a live performance. There's very little humanization to your velocity and timing - fiddle around with individual notes to give it a less rigidly-quantized feel.
When a piano piece is performed live (at least, one in this style of arrangement) there's going to be a lot of emphasis on using the sustain pedal to create natural transitions between notes and generally helping the piece flow better. This sounds like it was performed on a piano with no sustain pedal and very little sustain on the notes themselves, so it comes across as very mechanical :\ I'm sorry if this is harsh, but I see promise in your arrangement but the humanization just isn't cutting it here. You need to take what you've got here and put some serious work into velocity, timing, and especially sustain lengths on your individual notes if you want this one to get to a point where it's passable by the OCR panel.
Past that, No Escape gave some very good advice on reverb and panning that would help augment the decent-but-unimpressive samples that you're working with that I'd highly suggest you take to heart You've got a decent arrangement here and if you're interested in working on it a lot, there's no reason you can't get this one to where it needs to be.
Best of luck if you choose to pursue this one further!