I am so happy! I haven't been on this site to say this because I wasn't sure it was true, but Bud seems to have come out of breeding season. I spent three weeks at my parent's house working in Connecticut, and took Bud with me. He immediately went back on his potty training schedule, I think because of the change of location. He knows that that house is where he's potty trained, I guess.
He was still charging, headbutting, and biting though, until about two days before we left. Since then, he hasn't been as orange, and I have no trouble taking him out of his cage to get him to the bathroom!! I can even leave the cage door open, and he won't try to jump out and dive bomb me.
And I think I solved one reason he is so aggressive in his cage here at home. He had lots and lots of fake leaves covering the front of the cage, and I thought it gave him privacy. But I think he felt that I was sneaking up on him, because he couldn't see me! Even though he wasn't in breeding season, he was still jumping when I would come to feed him. So I took off some of the vegetation, and he's a lot better!
Also, I think he feels trapped in a corner because his perch is so close to the top of the cage. I was trying to get him as high up as possible, but maybe I need to lower his perch, get higher wattage lights, and put the cage up on a table or something, even though it's over six feet tall!
I am so happyyyyyy! My little green baby is back! I know he will become the Carrot Monster again some day, but I hope this is a beacon of hope for people with big orange monsters out there. 
