They may be hard, but that's what practice is for.
Arrangement wise, I don't know the original, so I'll comment based on your arrangement alone. I know there are times when freestyle playing creates better emotional music, but pianists can spare a foot to keep tempo. Organists, not so much. My advise would be to get a silent metronome app or something to help you keep tempo. I also suggest either get a stereo mic or mix your mono so that it comes through both speakers. Audacity might be for you. Other than that, I love the arrangement. Very soothing.