1) I don't think she is an overrated singer. I believe she is one of the artists that has the voice of this generation. There are others as well
![:)](http://www.atrl.net/forums/images/smilies/images/smilies/smile.gif)
She has an incredible voice, but like Katie stated, those too young may underrate her voice. However, I really enjoyed the Back to Basics era. That really showed me her powerful vocals.
2) Genie in a Bottle, Beautiful, Fighter... etc. Yes.
3) I would go with Icon.
4) No
5) I think it is possible. She is great with ballads. Castle Walls gives me hope. I wish her the best.