Hi surfbaby -
Have you spoken with the GT coordinator/teacher in your district? Even though programs may not officially start until 3rd grade, the GT person might be a great resource for you. In our district, services didn't start until 3rd, but our GT coordinator ended up teaching my DS accelerated math when he was in kindergarten. Although you might not get that kind of service, I'm sure the GT person might have some good advice, including suggesting a particular teacher who might work out best for the acceleration. The principal would probably have great advice on picking a teacher as well. For us, including the principal from the beginning has always been helpful.
2. If the teacher thinks your DS would be fine, I'd tend to trust her. My DS is a completely different kid at school.
3. I'd say the earlier the better re: timing. Maybe he can jump in at the start of the next unit.
I'd also suggest giving end-of-unit tests or even end of grade tests to make sure you're getting the right fit.
Good luck!
