Jesus in the Temple

We had an interesting and lively discussion last evening in Bible study. We have been studying the book of Luke and we were in chapter 2. When we started talking about Jesus as a child of 12 in the Temple(vs.41-51), people started asking alot of questions and providing various opinions. I must say, I found this very exciting because you can read a passage over and over and it's like you're skimming the surface and then SPLASH! you're immersed in it.

Several points here:
1. In that culture and time, a child was not considered responsible for his or her own sins until the age of 13. Jesus was 12 at the time.
2. If Jesus were of age and in the Temple telling the teachers of His intimate relationship with His Father, He probably would have been drug out and stoned.
3. No self- respecting Jew would have said "My Father". They might have said "Our Father".
4. Some translations say in vs. 49, "in My Father's house". I like the more literal Greek, "about My Father's affairs."
5. Mary was most likely relaying this message to Luke years later and held these memories dear to her heart.

Questions:
1. Did Jesus "sin" when He chose to disappoint and worry His parents in vs.48?
2. How did He know about "His Father's affairs"?
3. In vs. 48 again, If His parents were amazed at His knowledge, who taught Him?
4. vs. 50. Why would His parents not understand His statement, considering their hidden knowledge of His conception?