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.
Yes, so long as you are actually going to FIGHT to cause the change you want. Declaring war with a understanding that the armies will never meet and that no looting or anything will be done, that is wrong.
