I can't tell from your post whether there have been behavior issues/attention issues all along or if they are sudden. If they have been there all along to some extent, you should maybe look into ADHD. If there is a school psych ask if there are rating scales that you and the teacher can fill out. If it is ADHD and you decided to medicate, that could potentially solve some of the attention/behavioral issues (if you go that route--I'm not pushing for medication).
It doesn't sound like a skip would be a good idea, and you should advocate for differentiated work in the classroom. Our school system requires kids be near the top of the NEXT grade before they will approve acceleration. The kid has to be practically perfect. They don't want kids to move up and then struggle. Being at the top seems kind of silly as the goal should be for the kids to be challenged, but I would say he should test at least 50th percentile for the next grade up in all areas (like writing, behavior, math, etc). Ask them what assessments have been done and how they determined his level. I don't know what independent test you had, but my experience is that the Woodcock Johnson grade level equivalents are pretty crude. For instance, for math it put DS at a 4th-5th grade level equivalent in early first grade. There was no way DS would have done well with the school's 4th or 5th grade level math curriculum at that point.
