Synthesized answer
The provided passages do not explicitly list unanswered questions. However, based on the information given, several aspects of Tally's world and the choices she faces remain open to further exploration.
For instance, the ultimate fate of Shay and the consequences of Tally's choice are not detailed [1]. The passages also do not explain why Shay is hesitant to become pretty or what "life on the outside" entails beyond her preference [1]. The nature of the "high-tech paradise" and the specific reasons for the mandatory operation to become "pretty" are not fully elaborated upon [1].
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: Uglies by Scott Westerfeld Description: Tally is about to turn sixteen, and she can't wait. Not for her license -- for turning pretty. In Tally's world, your sixteenth birthday brings an operation that turns you from a repellent ugly into a stunningly attractive pretty and catapults you into a high-tech paradise where your only job is to have a really great time. In just a few weeks Tally will be there. But Tally's new friend Shay isn't sure she wants to be pretty. She'd rather risk life on the outside. When Shay runs away, Tally learns about a whole new side of the pretty world --…