What patch are the finals of league of legends running?

4.14, which is why alistar has been permabanned all tournament.

Do they get to practice on the same patch that the tournament is on? It would be pretty confusing to practice on live and play on an old patch.

Yes, all their scrims are on 4.14 with tournament realm accounts, that's why they generally are only scrimming the other worlds teams.

Which was utterly idiotic. Lets release a tournament patch for worlds that includes a blatant imbalance requiring a champion to be permabanned. This has basically reduced the number of bans at worlds to 5 and significant limited the ability of teams to ban out specific champions.

I agree, but it is what it is, at least they provide the teams a way to practice specifically on that patch, and don't take it away from teams eliminated from worlds, so the remaining teams still have scrim partners.