Excactly, they would still have to abide by the law like every citizen.
1.
The chantry itself is a lie, or at least what chantry indoctrination is based on. It is nothing like the real church. Why else would the maker be disgusted of humans. At least our beloved(sarcasm) divines should be able to earn his forgivness. Why create the blight to destroy humanity as a whole if you are just upset by the magisters attempt to enter the golden city. Where is the divinity in using mages and templars as a second army in case of an excalted march. And don´t refer to the Qunari, because every other exalted march was against mages or elves.
2.
These are not laws. Orlais and the chantry forced their dogmatic view of magic on everybody else. I played both games several times, and I never met anyone being afraid of mages besides Orlaisians, Templars and Chantry Accolytes. The rest doesn´t bother with mages or magic at all.
1. Head cannon. There has been plenty in game supporting both sides of the debate with nothing substantial on either side. It is what you believe, but nothing in game says so. The same type of god who would destroy an entire city to ash because he was mad at his people, the same god who would flood an entire world of his people, seriously religion isn't nice. Most of the exalted marches had nothing to do with elves or mages.......
2. They are laws, the nations submit to chantry authority over the circles. Gaider has said this. This is why the boons to free the mages doesn't work. The king of ferelden can ask and the chantry says no. Also, the chant and the chantry predate orlais. It actually started in Tevinter before Orlais was founded. Also, read asunder some time. The villagers are terrified when they find out there are mages. We have also met some terrified fereldens when they meet a mage and some residents of kirkwall seem terrified as well. As we haven't been anywhere else, I can't argue that.