1. The genre of the play is tragicomedy because the play is based around Cal and his relationship with Andre. Also the rest of Cal's family had some sort of relationship as well. Along with the tragedy of Andre dying from AIDS there is comic relief from the rest of the family. "...you can buy your little girl a Good Humor" "They still make Good Humor?"
2.The significant spectacle may have to be the white ballons which symbolizes the purity and letting go. White symbolizes purity and once the balloon was let go by someone, each of them took a moment and said something that they remembered of Andre then let the balloon go.
3. Andre's mother never speaking may mean many things. It can mean she was very upset with Andre's death, the way he died, how he lived his life etc. Either way it made the story even more tragic than it had to be, knowing that he wasn't accepted by his mother (because she didn't know about him) in my opinion makes the play a tad bit more sad. So that may change the theme of the play significantly.