A Too on average takes about 1-3 years to fully settle into a new home. Give the bird at least 1 full year before determining whether its going to work or not. I have a similar post I responded to not to long ago about how to ease your new Toos transition:
http://www.parrotforums.com/cockatoos/18062-i-need-some-cockatoo-training-tips-please.html
As far as the plucking goes:
You can try to provide the perfect environment: lots of foraging toys, phone books (to tear apart), all different levels of destructive toys (mix of ones that take them forever to destroy and ones that can be finished in seconds). You want to challenge the bird mentally and mentally keep them stimulated ALL day. If you can, keep the bird as little caged as possible. Be EXTREMELY CAUTIOUS that you don't give your Too to much attention to distract from plucking. This can lead to a Too that becomes spoiled (spoiled Too = dangerous Too and very unpleasant to live with). Try to encourage independent behaviors. Stuff that requires thought and challenges them mentally. Sure you could physically hold your Too all day to prevent it but you will destroy your bird this way. It is so vital to encourage Toos to be independent.
Never ever expect the plucking to stop. It may go away once he is settled in but never
expect it to really ever disappear. Go ahead and except that he may be this way for life (and more than likely will). No matter if you provide the perfect environment and do everything right, he may still pluck. There is no cure once they start, you can only try to redirect the behavior. Look at it this way, he is an addict. Addicts are addicts for LIFE, they will have stretches and runs of remissions but there will ALWAYS be relapses. He may get settled in and not pick for months (or years), then you come home one day to a pile of feathers on the floor for no apparent reason. You cant give any mind to it when he does it, pretend that it doesn't happen. If you give any attention to the fact that he plucks, it will make it much worse. Look at the situation like this: he has a problem within himself that makes him pluck, there is truly NOTHING you can do to fix it. Love him for him and forget the feathers. Its hard to live with a plucker/shredder as you will always have to feeling of 'if I did more he would stop', not true. You must remove your own emotions and detach yourself from the plucking behavior. You have to except this behavior.
Rome is a shredder (she barbs her feathers). In the beginning I foolishly thought I could stop it. I was hard on me to come home and see a pile of feathers, it bothered me because I felt that I was doing something wrong (sound familiar? This is how spouses feel when they live with an addict). It took a bit to move past that. I provide her with the best situation possible for her to live in and have excepted that this is who she is. Sometimes she goes a month or two and then decides to shred for no apparent reason. It just is who she is and forever will be.
This is all so long to read but unfortunately Toos are complex and they require more than a simple explanation.