Well, I am definitely no expert. I've only been on this Gifted child road for the 2 years 9 months we've had my daughter. She too did EVERYTHING early. She has always gotten along only with kids older than her and has a fascination with academics. She's stubborn too but not about academics... i think she's shown us what she knows for the most part (but then how would I know?) :-) My 10 month old seems to be gifted too.. we're still figuring him out. He's a very early talker at least.
Anyway, all this to say: I don't have a ton of experience but it sounds to me like giftedness might be what you are dealing with. Refusing to do certain things like brush teeth and other routines could just be going through that INDEPENDANCE phase that most see at like 2-3 years old... but with gifted kids all that comes early and is often quite intense. Most of what you describe does sound at least advanced to me. And that can be hard to sort through.
Be patient, be firm. Since he does understand so much (emotion etc...) for his age don't be afraid to have slightly higher expectations of him. I got a lot of dirty looks for being "strict" with my daughter at a young age but I just tell people "I only expect from her what she has already shown me she can handle". That usually shuts them up. It's not the case for all gifted kids but in our case DD is socially advanced along with her giftedness... so holding her to a higher standard of behavior (of say a 4-5yo when she's not even 3) IS something she can handle and will only make her stronger and a more patient, well-behaved little person. And patience is something they'll always need because they're little brains go faster and deeper than most people around them and patience is key.
Good luck!
