OP Testers
You know how in software there are white hat hackers. Their job is to hack a system to the extreme in the hopes of finding holes early and patching them? Why not have a group of people who's sole job is to find the OP builds or ability paths. Ok, item builds are complex but ability paths are a known permutation set. There aren't that many. I feel like if you had someone doing that, you would have easily caught Ryze's perma-root problems, it was something even I knew would happen when he was released. I think the Ryze problem is a wake up call to really start testing these abusive possibilities. Try a max CDR champ. Try an 800 AP build or a 5000 health and 200 armour/MR stat line. See what happens