kdoelit- yes, your son sounds gifted and intense. Many people here can probably relate.
My DS is now nearly eight, and I find that if I need to get things done, I still have to check in with him about his "plan" for the next hour or two. We lived through the mischief, tantrums, intensity, etc., and to a large degree are still living it (minus the random mischief and tantruming as an extreme sport).
Here's something that seems to work with busy, smart boys (and maybe girls, but I don't have any). Engaging the hands and mind together- building materials (free form), art, crafts. Later, music lessons, complex board games, writing stories, a small amount of creative video gaming (e.g. Minecraft), Reading of course-- physically holding a real book and burrowing into it for an hour (I like that too!).
Also, my DS needs a lot of outdoor, unstructured playtime- at that age, the swings at the park were great for meeting sensory needs.
