Bansystem changes
I have an idea how the ban system could be improved At first I want to say that I only consider ranked games for these changes. So my idea is to punish the summoner depending on the reason he got reported for and had been proven guilty. So if you had been proven guilty for feeding multiple games u will get demoted.
If u had been proven guilty of harassment, negative attitude or something like this you will be chat banned and can only send 3 messages per game (first ban is for 2 games increasing with each ban).
If u went afk multiple times you will still get banned for an amount of time.
In order to decide who should get banned you could bring back the tribunal. Maybe give Hextech chests or keys as a reward to the "judges".
I would be glad if Riot considers my suggestions and think these changes would positively impact the game.