I had many of the same questions a mear 6 months ago before I got Finley. I did not become the 3rd wheel and my birds are both bonded to me. I do and did keep them somewhat separated and it was a while before they got along to where I could trust them together if I didn't have full attention on them but we're there now. I was afraid they would bond to each other and they still could I suppose but probably not. Ollie my 1st bird hasn't changed at all, he is still a perfectionist and perfect and has still yet to bite me EVER! He always obeys and is smart and amazing. Our 2nd bird Finley is a sloppy, clumsy, and bitey doofus but he has an endearing quality to him that makes him very forgivable and likeable despite his other issues. He is the quintessential middle child, guess that means eventually I will have 3! Haha. Finley is louder than Ollie and at times they feed off eachothers noise but luckily neither of then scream for no reason. There is always a reason that I can identify so it's not bad at all. I do not regret getting a second bird but at times it is harder and I do feel like I ignore Ollie a bit because he is such an angel and Finn needs so much time but I hope he understands, he hasn't treated me differently so far so that is good. Another thing that is different is that we have more cages and more bird things in general now, our house looks like a bird sanctuary. And..there is more to clean up but it's not that bad because at least both my birds are potty trained so it's mostly just food crumbs and such I sweep up like 3 times a day. I Hope this helps! For more in detail you can follow our journey linked in my signature. (I know you have commented before).
Advise: Try to get 2 birds of the same sex so they are less likely to bond. Keep them apart especially in the beginning until you know the 2nd bird has bonded to you, a good way to tell this is that if he contact calls you when you leave the room and keeps calling you but doesn't contact call your other bird if he leaves the room as frantically as he calls you. That's how I knew that Fin has bonded to me, that and he will flop onto his back but only on my lap. Have patience! I had to learn that Finley is NOT Ollie and how I trained Ollie will not necessarily work on Finley. Don't get discouraged if your second bird bites more or isn't being trained as fast, each bird is an individual.
I know its more cleaning and work ect, all of that is no problem to me and Xander is so chill i could spend more time raising another bird but he will still get the same attention he gets now. His favourite thing is doing his own thing but with me in the room. He would be happy without any attention as long as im there. He is such easy work.
