I hope you're right about the behavior going away after puberty. We blocked the fridge so he couldn't get under it, and he was actually much better today. He wanted attention and cuddles and I didn't get any nasty bites...You just need to hang on until puberty is over and done with, Push through, most time the nasty bad behavior of puberty (which they literally have little or no control over) will go away, especially if you have not allowed bad behavior to become habit!
ANd "trim" means clipping a small part of some feathers on his wings, just enough so he cannot get any altitude when trying to fly. Feathers grow back, so this would only be during his puberty.