Shellymos, your son sounds amazing!
Here's our experience on school and testing. My DS4.5 is going to a play-based preschool again this year, and he likes it well enough. (He told me the other day that he's sad about going back to school, and that he hates it, but I don't really believe him about the hating it part! We'll see, I guess.) He is learning respect for other people, how to follow rules at school. He's a bit iffy on the following rules at home! but he's extremely proud that he's never gotten a consequence at preschool.
So I'm happy about the preschool.
We had DS tested at 4.1 (SB-V) because we were thinking early entrance to kindergarten. He more than met the district's requirements, but we followed the tester's advice to keep him home for another year (his preschool is just a few hours/3 days a week). We haven't focused too much on real homeschooling, but he's still learning stuff. We'll do the achievement testing when he's 5, and apply to DYS. For all the tests you are being offered, that sounds like a good deal to me.
As things progress (quickly with these kids, I'm finding!), I'm starting to think that we'll probably end up trying to skip kindergarten when that comes around. (However, we just got info about a new STEM k-8, spearheaded by a mom of HG kid, that will have plans in place to put gifted kids at their level of learning, so we'll see...)
