The Rhodok's council thing. 1.How exactly do you enforce the rules against weapons without weapons. 2. A bunch of important people with rich friends with no weapons/heads of the enemy nation with no weapons, seems like a very stupid idea to not expect an attack during this.
1. The rules are only enforced once the council is over, presumably. In any case, "rules" and "law" in Calradia are little more than pretext to allow those with the strongest armies to do what they want to anyway. 2. The practice is pretty stupid, but perhaps the Rhodoks were not expecting any attacks, as the meetings could be held in secret or in areas well-protected, suggesting that Rhodokian intelligence had failed, or it was a complete surprise attack. Maybe even the guy with the weapon informed the enemies of its location, then rushed in to "save the day". The game is reasonably careful in showing that there are two sides to every conflict for the claimants, and that pretty much every would-be ruler is not above cut-throat tactics.
The bigger headscratcher is the location - it's referred to as the "Field of Jelkala" by Kastor, implying that it was in front of the city or at least nearby. In that case, why was Graveth the only one who could defend them when a (theoretically) fully garrisoned city was right there that they could rush to for safety? Unless the implication was that Graveth (who is the lord of Jelkala) was going to lock them out if they did not vote for him, but still...
How bandits without horses are shown as having horses on the map, which allows them to catch up to you, and then you can't run away for whatever reason, despite the fact that you do have a horse.
You are thinking of deserters (though why they have them is still a valid question) and all bandit units except sea raiders have a chance of a mount.
Generally, when you encounter an enemy force on the map, you go to a parley screen before the battle begins and meet the enemy commander face to face. Presumably, after this both armies then separate before the battle begins and charge from a distance. However, why do looters and bandits do the same thing? They walk up to you, announce their intention to murder and rob you, and then withdraw (often on foot) two hundred yards away before the battle starts.
Maybe they're actually yelling at you from far away, and if you answered, you were also yelling back?
It could be a cultural thing, where two leaders meet on the neutral ground between two groups, issue their demands and once the demands have been issued (and rejected), both leaders return to their troops and commence the battle. So both you adn the bandits were away from your troops, then went back to them.
Why do ransom brokers randomly move from town to town? It seems like either staying in on place where their customers/suppliers know they can be found, or at least moving in a fixed, predictable circuit (e.g., people know that the Ransom Broker who covers Dhirim is currently in Suno, but will be in Dhirim in four days) would be far better for business, both letting manhunter-types easily find them and sell them captives, and allowing slave buyers or friends/family members to find them and pay them to buy a slave/free a friend or relative.
Is it possible that ransoms aren't all that common? Most counts/emirs/jarls are ransomed directly from the person who was captured, and most prisoners are just held in the dungeons in a town or castle until the lord sees fit to release them. The ransom broker probably makes his business solely off bandits that run around capturing farmers and the player. Not to mention, when you're associated at all with bandits (which, even if the bandits don't sell.to.him, are mostly what the player will be selling), you're not exactly in a safe occupation. There's plenty of reason to get to a town, do.business, then disappear without a trace.
they follow rumors of active wars and recent wars, attempting to find cheap prisoners to sell off in over-crowded prisons or via travelling bands looking to offload their human cargo.
They actually explain that buying prisoners from you is their hobby when you first meet them - they usually go out on commission to find someone who was captured and already sold (probably to one of their friends) and then arrange for ransoms to be made. When they buy from you, they're basically cutting out the middle man of whoever they pay a ransom to normally. So, the reason they move is probably because they're doing their main job and they're picking up prisoners from you as a side deal. But if you're hauling prisoners, they'll take them off your hands to see if they can get some good coin additional to their normal funds.
Alternatively, Slavers simply aren't popular, I've been attacked by bandits countless times while trying to buy Groceries, a slaver might find the same if he moves too slowly, also he has to offload the slaves at salt mines and so forth, having a predictable route means his cargo can be more easily liberated by their Irate friends.