I would lean toward the casting as the least invasive. From what you say I would not trust the "one size fits all" doctor.
I knew a girl in college who had multiple surgeries at Shriner's when she was very young. I would not say that her long term results were very good. She could use braces and crutches but generally used a wheelchair. However, she was born in the early seventies and I don't think that nearly as many babies with issues such as prematurity survived then. She also did not have an effective family advocate and felt like she was treated like a guinea pig. I don't know how much impact the surgery had versus the relative lack of effective physical therapy available at the time. I also don't know how much imact her efforts or lack thereof at physical therapy might have had. The sad thing is I strongly suspect that if she were born today her disability would be virtually undetectable with proper treatment.
I would definitely look into all options and try to wait on anything permanent until your dd could be involed in the decision making or at least understand the reasons better.