Questions about my kitten...10 points for best answer!?

Kneading your arm is actually an even bigger sign of contentment than purring! That is so sweet. It sounds like you have a very loyal companion. The tackling your feet and hands is just normal, playful kitten behavior. He will most likely outgrow it. If he doesn't, he still won't be doing that nearly as much. Also, sometimes they will do that just to get your attention. By yelling "NO!", you could actually be reinforcing the very behavior you don't want. If you ignore him when he bites you and turn your back to him or leave the room, he will realize it isn't any fun and he is getting a consequence he doesn't like. Just make sure to reward any good behavior you like with kind words and scratches behind the ears, etc.