I shall tell you a story about ds which will hopefully make you feel better. I thought I'd told you all this before but it seems apt to tell the tale again for Star's benefit. When DS was about 2 there was one particular member of nursery staff that he loved. He talked about her at home, he ran up to see her ever morning at nursery. She was very lovely so I didn't mind, plus he was quite obviously her favourite. One evening I was late home from work because court over-ran, Alex was in an evening appointment so we were going to have trouble picking DS up from nursery. This particular member of nursery staff offered to drop ds home, which was fabulous (this is before we loved two doors down from the nursery obviously). We said thank you very much and relaxed. About ten minutes later they arrived and ds started getting upset when he saw me. I picked him, said thank you and closed the door...... Well, DS started screaming and crying, trying to open the front door shouting "I want my mummy". I said, "I'm here you silly billy". He replied "You're NOT my mummy, is my mummy. I don't love you, I love . Now GET MY MUMMY!"
M is still showing a strong preference for being with me, but she does love spending time with her daddy. I know it's upsetting when they seem to reject you, but it is knackering when you're the one in favour! DS hated DH until the age of about 3. He would recoil or scream if DH touched him. It was horrible. They're good friends now, but he's still a bit of a mummy's boy.
Star - I've read or heard that they don't really start to learn or remember about consequences until they are three. They know that if they push this, this will happen, but they don't remember that if I push this, this will happen and I'll get told off.
Pistachio - DS was the same as your DS. He used to end up head butting me in the face because he would struggle so much. It's so difficult when they start to get a little bit of autonomy. M can get grumpy about being carried but her response isn't as violent and she doesn't weigh as much as T so is easier to manage.
CSWS - Yes it appears that just one tooth is causing the grief, however for us it is just exacerbating the already dreadful night-time sleep pattern we had!