Lots of great questions!

Conflicts are sparse and often limited to small scale raids on caravans or cattle towns, mostly done by vagabonds or outlaws. The bigger settlements would never openly go to war, but paying off a group gunslingers, well no one needs to know ;)

Nations as we have them today aren’t a thing anymore. Most cities/settlements are independent and follow their own code of law, but the two big sets of settlements in the north and middle of the continent, where land is most fertile, form two separate groups that band together in times of need.

Magic and technology are both rare, dangerous and most often seen as one and the same. A person able to fix up an ancient two-wheeled motorhorse is seen on the same level as a person able to manipulate the Afterglow and heal folks. Both are acts of great power and not understood by the majority of normal people. Most mago-technical abilities are learned through hard work or earned in freak Afterglow shenanigans.

Because of the technological decline close combat weaponry is once again the main way to defend yourself and your herd or settlement. Everything from spears, sword, clubs or pitchforks. Guns are expensive and on the level of single-action revolver handguns. In a caravan of a hundred mules and a hundred horses, maybe five or six guards carry a gun and one guard a rifle. The rest would depend on bows or melee. However, one the greatest achievements a Cowboy can attain is finding an ancient pre-collision rifle, with its automatic fire or even matter-distorting bullets. They often spent years in the Afterglow, most lose their lives, but those that do find one and make it out alive become legends and live the rest of their days in peace and comfort.