Okay, I've done some thinking.
I have 4 US things that I'm worried about changing my full name on- passport, social security card, bank accounts and drivers license.
Passport is easy- statutory declaration.
Social security card- pretty sure I can do that through the embassy with the statutory declaration, but will double check.
Bank accounts- Not sure whether they will take the statutory declaration or not but I can get it legalised by the US Embassy which may do the trick. Also presenting a social security card & passport in my new name may help. Worst case scenario, I should be able to open a new bank account with my new name as long as my social security card has been changed.
TX drivers license- the one I was most worried about, but apparently, I can change my name on my TX drivers license by mail, and the form to do so implies that I may be able to just use my marriage certificate for the kind of name change I want. Will also enclose the legalised UK statutory declaration and hope for the best. Worst case scenario- they won't renew my drivers license in the new name when it expires in 7 years. I'm not planning on moving back to the US so not a huge deal if that actually happens (which I don't think it will.)
I also have my US naturalisation certificate, but I don't think it's compulsory to change my name on that so I'm not going to worry. Anything else in the US I can just use my marriage certificate to change my last name as they likely won't have a record of my middle name anyway.
So yes, not quite as straightforward as I had hoped, but I think this is important enough to me to do it anyway. Out of all the name change options, Andrea Maiden Married is the only thing that feels right so better to endure some headaches than go through life with a name that I'm not 100% comfortable with.