Draft a written agreement with the terms you two agree to. You may want to hire an attorney to do that.

You can certainly try to argue it. It would be your burden to prove and prove what he really should be earning.

You should file a request for default.........Good...

No, not necessarily. You still need to prove your case. However, it does make it easier to be successful .

You will need to file a petition for contempt with the court first and the court should be able to assist you on that.

File what is called exceptions: https://www.calvertcountymd.gov/DocumentCenter/View/40632/Exceptions-Form-PDF good luck.

You should have the kids talk to their dad. If he still wants them to go and they decide they do not want to, he could file contempt against you,...

Attorneys cannot solicit clients in this forum. You can locate an attorney on this website and reach out to a few to schedule a consultation.

Unfortunately,this is something that will require you hire an attorney as this question can not be answer in this limited forum such as this.

The best way to accomplish this is for you two to reach a signed agreement that resolves all issues between the two of you.