Perhaps those that practice elemental magic begin to take on characteristics associated with their chosen element. For instance, an earth elementalist might be prone to agoraphobia, while air and possibly fire elementalists might have problems with claustrophobia. Water elementalists might always seek the path of least resistance. A fire elementalist might have a cat's opinion of water. This could also apply to physical differences. Fire elementalists might have a freakishly high metabolism and a permanently high body temperature. Water elementalists would probably never get dehydrated, but might slow down a lot when it's cold. Etc, etc.
In cases where a person has accused another of a crime, but there are no other supporters of the accusation or defenders of the accused, and there is not enough evidence to support one party or the other, the two people involved, or their champions in some cases, must duel in the presence of the local ruler or leader. The loser is assumed to be lying and punished accordingly.
It is not considered a crime if a ship's crew mutinies against a captain that is obviously unfit for the post (dangerously incompetent, insane, or overly cruel). Assuming, of course, that they can prove it.
Rivers and other natural boundaries are used as political boundaries as well.
In addition to the Thieves' Guilds, there is a hierarchy that all thieves are part of. Rank is based on skill, and can be raised or lowered at any time. The Queen of Thieves, the greatest living thief in the world, is the ruler. Guildmasters answer only to her, and she answers to no one at all.
For those familiar with cantrips, you know they are minor acts of magic that have hardly any noticable effect on the world. For example a cantrip to make your food taste better won't heal you any more, or be any more nourishing, just won't make it so hard to get it down. A light cantrip certainly won't be able to blind or even distract anybody, but you might be able flash it to signal someone looking at the right spot.
What if children's nusery ryhmes were a form of cantrip? Like the "Rain, Rain, go away, come again another day." One child singing it wouldn't do more than spare her house a couple raindrops, but what if the whole village got together and was chanting in unison? Each one doing just a bit might actually be able to divert a whole storm...