You might want to consider getting further testing to determine the possibility of giftedness with or without ADHD. It can be hard to tell what's going on at times but you need an expert with experience in both giftedness and ADHD to guide you. Otherwise, you run a risk of getting a misdiagnosis or an incomplete one like we recently got.

I agree that the sensory stuff can be an indicator of sensory integration which can be managed or greatly rectified with occupational therapy or a sensory gym/diet; Lindsey Biel's book, Raising a Sensory Smart Child is very helpful.

Have you looked at these books?:
1. Different Minds by Dr. Deirdre Lovecky - http://www.amazon.com/Different-Min..._1?ie=UTF8&qid=1323700164&sr=8-1

2. Misdiagnosis and Diagnoses of Gifted Children and Adults.
http://www.amazon.com/Misdiagnosis-Diagnoses-Gifted-Children-Adults/dp/0910707677/ref=pd_sim_b_1

Very observant, creative, sensory stuff, master at arguing, selective hearing, etc., I can relate to a lot of what you were describing with my kindy son who's now 6 years old; we're in the process of getting further evaluations for him as well due to a similar situation. He's a visual spatial learner and your son may be as well. You might also have a divergent thinker who is going to buck the status quo.

Have you read anything by Dr. Linda Silverman?
See - http://www.gifteddevelopment.com/Visual_Spatial_Learner/vsl.htm

We found that my son did better with less structure rather than more structure and that he was better when he was allowed or presented with more challenging material. It sounds like your son isn't being challenged at school; yes, we've got the same situation with our kindy son - who complained on Saturday that his private, creative gifted school is boring. Yikes!