Re: 4 year old
gonelong, I can't believe you just posted this thread! My son will be four in August, and just yesterday I was thinking of making a very similar post. So, thanks for taking the lead!
His play has been much less structured than yours. We haven't done any fielding, and although he has an accurate (if inconsistent) throw, I haven't really coached him on it. I've also had problems getting him to use proper batting stance. My dad said not to worry too much about it at this age, but rather to let him get used to making contact.
He had been playing with the plastic stuff until Monday of this week, when I broke out the t-ball model aluminum bat and rubber t-balls. The results weren't nearly as good, and he got frustrated. I'm not sure now whether to stick with it or return to the plastic stuff.
Anyway, I'll be looking forward to seeing what is said in this thread.