I think trick rooms should make priority moves go last. With the exceptions of moves that causes the opponent to switch, they should always go last.
I dunno. If you do that, then low priority moves would have to go first. So a Skarmory could just Whirlwind you endlessly until Trick Room ends.
Please read what I wrote. "With the exception of moves that causes the opponent to switch, they should always go last"
Its still a horrible idea. Trick Room should not be in any situation rendering Protect, Prankster, Helping Hand, Snatch, Mirror Coat/Counter, Avalanche, Revenge, Fake Out, and all those other moves useless.
Oh and not to mention Focus Punch gets into overpowered territory.
The priority moves aren't all just there to just be quicker, they're there because they have specific mechanics based around their priority and your idea completely disregards that.