Fiction with a gem and a bridge on the cover?!?

[cardiacuk]

I'm hoping someone can help me find this book as it really affected me when I was younger. Some plot points I can remember include the protagonist having a homosexual encounter backstage at a theater, a character being killed by being stabbed in the eye with a pencil, and the protagonist not attending the funeral, and also the protagonist climbing a balcony at the end of the book to speak to a girl. I also remember dolls being involved somehow too, and a bridge being sabotaged. I must have read it before 1999, if that is any help.