Riot Transparency
One of the things that I think fuels much of the anger and misunderstanding on the Boards is the fact that Riot acts on information that most players don't get to see. Most players operate based on their personal experience or data from third-party aggregation sites. However Riot is sitting on a giant pile of data that no one gets to see. The recent post about traps games opens a brief window into the large amount of data and information the Riot has about games. I think the major solution to balancing problems is having a more open attitude to their players. They should create a place where Riot will release all of the data on the game that is relevant to balance. This would clear up misconceptions among the player base and allow them to more easily see Riot's point of view.
Another thing that is annoying is the lack of detail on game patches. Quick Gameplay Notes is good, but what Riot should have is a detailed version of the patch notes that references specific data they collected as well as the intended effect of the changes. I understand that not everyone is skilled at viewing and analyzing statistics, but Riot should make an effort to show people why they make the changes they do beyond simply stating things like "this will make X champion feel better" Clearly this data is looked at before Riot makes changes and when they decide which changes to make. Why not let players into more of the decision making process that Riot uses?