Temporary wars, to arrest a priest with no real consequences? Sounds awfully close to a friendly conflict and hardly SMA to me. I see a real problem with needing to declare war to arrest priest, but setting up agreements for a war deceleration to basically mean nothing is not a great way to handle it.
War with limited aims however are perfectly fine. You can say "I declare war with the objective to arrest this man and bring him to justice. Once that objective is achieved, I will accept a return to peace".
If you really want to be friendly, however, what you should do is ask the priests' judge to ban the priest, and then arrest the rogue. If the other judge refuses to comply, then yes, you should declare war with all the consequences that imply.
