Some birds just need a family without other animals, too - especially ones that are distracting and causing a ruckus frequently, causing the bird alarm since it may feel it's safety is in jeapardy as it was in the past apparently. Sorry to hear that the bird is misbehaving so badly. Highly intelligent animals needs much stimulation and often one-on-one stimulation from their owners - and birds need their flock-mates a LOT. many parrots need their owner's time about 4 hours per DAY. Pheonix is small but is out with us most of the time we are home, which is the only thing keeping her relatively sane.
Maybe that's the *present* problem with your Umbrella - so many issues with the dog that she couldn't handle the stress without a LOT of companionship? And the lashing out sounds just like fear from her, really. Heck, if you lived near here I know a few people who would take her to help her adjust back to trusting people - takes forever sometimes, but one guy here took 4 years on one bird. *sigh* Wasn't the bird a plucker too before? So there's tons of underlying problems, that this present time in your home brought up... not your fault though!
Anyways, I'm glad you have some good stuff coming your way with the training techniques you were... reminded of, I guess? It's hard when an animal goes through such hormonal changes! Pheonix screamed SOOO much more and ran away from ME constantly then! Looking forward to hearing about more progress. More learning opportunities for me here.
(ps - much of what I say is in no means saying you don't already know it. The way my brain works, I NEED to sort things out that way unfortunately... And I feel so sorry - for both of you - that your parrot needs a new home. parrots are SOOOO different from humans in their though-processes and their grouping instincts that people don't understand they are really really really hurting their birds with what they do... thus damaged birds that understanding people try to rehab and quite often fail unfortunately)....