I guess one thing I'd like to see improved is the intentional feeding / losing on purpose detection. Maybe look at activity during fights/engagements, if a player that's not the JG is in the JG during fights, increase their score. If the player is standing near the fight but not actively damaging or fighting, increase the score. if they're just autoing and not using abilities, increase the score. I'm not sure if things like this are already taken into consideration, but if not they should be.
I'd also like to see some sort of requirement of having spent RP before a player can go to ranked. maybe $5-10 worth of RP purchased. Just so there's a credit card verified on the account. It would be a useful way to keep the smurf/troll accounts out of ranked or at least to a minimum. No gift RP counts either, require from a credit card, on the account, tied to a name.