Problem 1:
Creep dots on the mini-map (red/green) are on top of the champion icons. Seeing champion icons is much more important so it should really be on top of everything else on the mini-map.

Problem 2:
Champion's icons are very blurry and it is often difficult to recognize champions on the mini-map. Also champion portraits on the scoreboard and the final battle report (victory/defeat screen) are also often very blurry/smudgy (difficult to distinguish).
One (very cool) way to solve this would be to introduce hero symbols instead of portraits (portraits are fine on the summoner's profile page though)

I attached a mini-map screen shot to illustrate what I mean.

There is a standard cryo icon on the mini-map and a symbolic one, also there is a symbolic soraka icon.
Now, I am a complete amateur at making graphics so they look crappy, but I just made them to illustrate what I mean not to suggest these icons in particular.




Note: I am running the game in 1680x1050