OTWOs edits are perfect. You can't make the letter too long because they may overanalyze it. I think you're showing a great deal of remorse and you mention your determination to not repeat the behavior and show works of repentence by trying to undo any damage. How long have you been df'ed? Is this the first request for reinstatement? How many know the specifics? Have you been attending every meeting?
Not that I agree with this line of questioning, but these are the things the JC is going to go over in addition to whether they think you are "truely repentant". It make take more than one request, especially if the timeframe on the df'ing is less than 6 months or if lots of people were affected.