It sounds like you have found a great fit for next year. I think information gathering is just natural for someone in your situation, but really you can't predict what's going to work or not work in the future when your child is just 3.
Though our DS (now 7) knew pretty much all the kindy curriculum before he went, we chose to not send him early, on advice of the psychologist who tested him, because kindy is a more fun way to learn how to "do school". Also, the school did do some differentiation. We then skipped 1st, which worked out OK, but still wasn't enough, so we transferred to a school for HG kids where they work baseline at 3rd grade, plus split out for groups at different levels (e.g, my son's reading group was doing 6th grade levels books). This latest HG school has worked quite well, and we are hopeful that he'll be able to stay there through the program, but you just never know.
Handwriting has been hard, as well as gym. My son was a perfectionist early on too (my mom remembers noticiting signs when he was 1). He did start writing letters very early on, but quit when they weren't turning out how he wanted them. He refused to try when we encouraged him, so kindy turned out to be a perfect place for learning to write (that was our main goal for kindy). DS's writing is still very bad compared to the other kids in his HG school, most of whom are a year older and had 1st grade, a writing year. But his teacher did not made a big deal of it, pushing just enough. A lot of good fit for highly asynchronous kids depends on great teachers. Sounds like you have one now.
I agree that it is quite important for kids to learn at some point that school is indeed for learning, and not just breezing through. Kids need to encounter some safe failures so they can learn to persevere, and it's better when this comes earlier. Bad when it comes in college.
