Once a divorce is finalized, most agreements are considered to be set in stone. However, you do have a chance to appeal a decision if you don't agree with it. It is unusual for an appeals court to overturn a judge's decisions in a divorce case, but it is not unheard of.
If you want to have your criminal record sealed or expunged, you need to meet the criteria set forth by law. You need to apply first for a certificate of eligibility. If you are issued this certificate, you may be able to get your record sealed or expunged, but receiving the certificate doesn't guarantee it. In many cases, individuals wishing to have their records sealed work with their attorneys to help make sure they provide the court with everything possible to make that seal possible.