My personal suggestion

So I played this game for about two or so years, and I stopped a few months ago. The main reason that I have stopped is because I lost interest in the game as it started to become stale, and very repetitive.

I have an idea that I do not know anyone else has ever done, but I think it would be a great idea to remove summoner spells altogether. (I know that the game is practically balanced around these in some cases, but honestly when you talk about a champion not having mobility, a five minute cool down blink is not going to make them that much more mobile). The reason I say this is because other games, like DotA and HotS (Heroes of the Storm), give you the option to use the D and F keys to activate other, hero (champion) specific abilities.

The biggest example of this would be Invoker from DotA. He is probably one of the coolest hero designs out of every game, and it would be awesome to see a champion like him in League.