Did you have an attorney help you with this process?
Some of the answer will depend upon the judge. Has the PO given you any ideas?
Six months isn't a long time. I would anticipate that you ride out the 6 month time frame. If it were 36 months, you would probably want to ask the court to get off early.
Yes, but only a judge can terminate it. An attorney or you would have to get it listed before a judge. Different counties have different periods of probation that must be met to fulfill a consent decree. If this is before the standard period of time for your county, you will have to provide the judge with a pretty compelling reason to terminate probation early.
Keep in mind that the consent decree program is your chance to show the court that you can stay out of trouble. Once you successfully complete the program the charges will be dismissed. You should then file a motion asking the court to expunge your record.
You should talk with your attorney about this, but I highly doubt that the district attorney and the judge will be willing to dismiss your charges before you finish the consent decree program. (The district attorney that handles juvenile cases would have to agree since you are on a consent decree, and I don't see her doing that.)
All juveniles are assigned a public defender (or conflict attorney) in Lebanon county, so I'm sure you have a lawyer.