1. Can you consult whoever you got her from or ask them to come take a look at the behavior? Cockatoos can be hard to read when you don't know the individual bird...
2. Can you let her out in a different room with lower ceilings ? Not taking her out, but allowing her to come out if she wants. You can't just keep her in there until you trust her......You likely have a very anxious bird right now who will not show true colors until she has some more freedom OR the same time, what you are seeing could just be excitement to get out---much like a puppy jumping and wining at the door...
You can't (in my opinion) build trust with a caged cockatoo...at least, not the kind you are hoping for. You will only get to know her by seeing how she acts outside the cage and that will never happen if you don't let her out..Unless you have a massive aviary--which, you don't.
Cockatoos in general NEED space and activity...you cage them too long and they get crazy...at least, based on my observations over the years.
Mine doesn't even like to fly, honestly...even though she can...Now, a galah likely would be more prone to flying, but still probably not as much as a smaller bird...I mean, yeah-- it is a risk, but that is the whole thing...You aren't going to be able to move past this if you can't get her comfortable and she sounds like she is feeling pent up...only way to tell is to test it..you have to see how she is when she isn't locked up or you will just continue to see this repetitive, crazy behavior (because she is captive and knows it--IMO).
Mine KNEW how to step up and wouldn't for 3 months...so this whole idea of waiting to have control could end up sabotaging your efforts...you aren't going to get it with your bird locked up and that means your bird will be locked up indefinitely..you are going to have to take a leap of faith at some point soon and be patient with her...
Again, my U2 wouldn't allow me to touch her for many months, but she was out (and unclipped) every single day and that is how we eventually bonded...you can't see their true colors in a small cage because they just want out most of the time..It was scary to let go of the control like that, but it is the only way we could have ever made it work. If I had kept her locked up, we never would have bonded because she would have turned inward and ended up with all sorts of issues....I know U2s are very different, but still, IN MY OPINION you are never going to read this bird if you don't let her out to see what she is actually trying to say with her body language..
3. Make it as safe as you can and then let her out- you aren't going to build trust if she is locked up because you won't be able to read the signals and if you can't read the signals, you can't move forward...and as controversial as clipping is, if your alternative is to wait to bond before letting her out for fear of your ceilings etc..that's an issue...and it will be an issue (1. because it's not doing your bond any favors and 2. because your ceilings aren't going anywhere).....cockatoos are stubborn as heck, so even one that trusts you isn't necessarily the most trustworthy could still chew...although, I imagine this one's presumptive fear/unfamiliarity with your home would likely make her LESS prone to go chewing on random things at this point, but still....I just wish I could emphasize the importance of activity and socialization for these birds--ESPECIALLY if they had a flock before or weren't locked up all the time...You will never learn to read your cockatoo while she is locked up---I would bet a chunk of money on that statement....now, once you know her, you will be able to read her better through the cage, but that will only be because, at that point, she hasn't been locked in the cage for days etc...but if you just keep her in there, I don't imagine you will see much progress...and you could end up with some added aggression in the long-run .
I don't want to put your bird in an unsafe situation, but I fear that leaving her caged will be worse in the long-run...so take it for what it's worth I guess.