Maybe she's gotten worse over time, but it's not like she was wholly uncontroversial as a teen. Perhaps the controversies hadn't been severe or numerous enough for the public to view her as being a wild child, but there were signs that she wasn't as good as some people wanted to think, and she was portrayed by some better than was actually the case.
Yes. I believe Miley Cyrus has been waiting for her big reveal. The big reveal being that of her actual self. She has portrayed a child star for so long, and that has surly had an impact on how she has been able to act in public. Now that she is an adult, and out of the child star spotlight, she has been able to express herself in other ways. They might be a bit overstated, but I believe she is being herself for the first time ever.
This question can be interpreted in different ways, and one might suggest that the "realness" of a person is dependent upon recent events in their lives. Since she recently broke an engagement to someone she loved, it might be her natural reaction to act out and look for attention from other sources. With celebrities, it is difficult to tell whether or not a personality is real or manufactured for publicity, but a person's actions are often based on choices they have made about how they want to be portrayed. Therefore, those actions are always the "reality" of the person in some sense.