two year old--hyper and picky eater

I am the mother of a very very very active two year old. He is constantly on the go from the time he wakes up, until he falls asleep. He is also a wild sleeper. He is very defiant and stubborn. He will also hit or kick if he is told 'no.' I purchased a homeopathic remedy called 'Kid's relief' on yesterday. I gave it to him this morning before he left for daycare, so I'm not sure if it has taken effect. His tantrums are pretty intense, to the point where I'm afraid that he will get put out of daycare. He also grits his teeth. The last issue is he is an extremely picky eater. I can't get him to eat meat. He will only eat apples, cheese, pop tarts, mashed potatoes, oatmeal, raisins, craisins, crackers and a few other foods. It's very difficult because he's been eating these foods ONLY for the past year and refuses to eat anything else. I try to get him to eat vegetables, but to no avail. Is there anything that I can give him for that?

He had ear tubes placed in February of this year for chronic ear infections because fluid was not draining out of his ears. As a result, he is somewhat behind with his speech. Other than that, he is a very healthy child. He's 33 lbs and 37' tall. I had a healthy and normal pregnancy.