1) If Luke was the only hope, why didn't Obi-Wan or Yoda train him when he was younger?
2) Why didn't they change Luke's last name? Couldn't Vader have just looked up Skywalker in the intergalactic phone book?
3) Why didn't they train Lea when she was younger. Why was she a princess anyway? Is bail the same as a king? Padme is no longer a queen.
I could understand Yoda and Obi-Wan giving them to "parents" to care for them as babies. When they got a certain age, why didn't they take over responsibility?
Would Vader or Palpatine sense the Force being used in their training. If so why didn't Vader ever find Obi-Wan? He supposedly used the Force to survive on Tatooine, right?
It just seems like to me, if somone is your last hope, you would utilize him as soon as possible.
We all know the real reason. In 1977 it was risky to have a child be the star of a feature movie, and I don't think Lucas intended for Luke and Lea to be sibblings in the beginning hence all the incest.