I agree with Tensei-San about the reverb...you should decrease it a little bit, so that the pieces won't sound so muddy. As for the gain, if you can't increase it anymore, don't worry about it too much...piano pieces tend to be soft anyway, and listeners can always turn up their volume.
The actual arrangements are beautiful...they make mine sound like beginner Suzuki Method pieces. ;_; It's so great to see arrangers from Japan are interested in OCR, and it would be a crime if these weren't accepted on OCR.
I don't know how to translate "Temporal Eloquence" into Japanese, but my interpretation of it would be something like "fluent in the language of time."
Thank you for sharing these pieces, and good luck with your submissions! I hope to hear more from you in the future.