Yi is no problem at all, you just think he is because he's a silver champ. I don't understand why you want to address him being good in low elo and bad in high elo so much. Its simply put that hes a vulnerable melee skirmisher but he can be taken down easily by cc and teamfights but sometimes people don't play against his crap early game and get demolished after he snowballs a few kills.
I recommend to remove all Yi nerfs and what ever changes related to him and call it a day because the only problem now is your 9.10 patch. He is not unbalanced, he's Yi thats what he is.
Don't like Yi? Well you wouldn't believe how many bad skilled iron, bronze, silver, gold players think the same.
The point is they don't know how to play league of legends so why should a beginner champ and his mains suffer because of that?
Funneling? Well guess what, not every Yi has a perfect duo to play with.