Hello,
my daughter is a bit similar to yours but then, she is a few years younger. She can concentrate for a long time on things she is interested in, but won't sit or listen much in a classroom. She doesn't like going to sleep early, either
My theory is some kids are simply bored at school. Maybe teachers can't present the facts in a manner they would find interesting, or maybe they are explaining things they know already (or they think they know).
About bedtime, we simply accepted she was not sleepy so early and now she is allowed to stay up with books, jigsaw puzzless or maybe a calm cartoon. We are all happier with this arrangement
Wishing you the best of luck and please don't worry if the teachers tell you there is nothing to worry.
About rearranging the letters- maybe dyslexia? Or simply, she might have found the exercise too easy and was trying to make something funnier / more creative with those letters?