Molly - What is this about anti-gay marriage etc? I don't remember anything of the sort from that book.
Yes, it talks about "The Queen" of the aliens because they are a hive, and so we talk about their leader and chief as their "queen" just like we say "queen ant" or "queen bee", and you would naturally expect to kill them all by taking out the queen, just like you do with an ant or bee colony - she is actually called "Hive Queen" in the book. Would you have been happier if she were called "The King"? (In that case, I suspect you would be outraged that the female of the species has been robbed of its rightful title 
)
"one gifted boy (not a girl... too many years of evolution stacked against female qualities like empathy, kindness, cooperation..)"
Have you read the book or just skim-read it because you found it boring & not good enough on the feminist/gay agenda front? It's clear about the importance of qualities like empathy (they specifically checked for his when questioning him re the fight he got into in the beginning), decency, cooperation, etc. (Having said that, someone with 'too much' empathy & kindness would arguably fail as a military leader, and would certainly not carry out the final assault that saved humanity)
I didn't feel that there was any sexism in this book. Candidates (girls as well as boys) are left free to work out their relative functions in their groups, to rise up to leadership as their skills & achievements are recognised. In fact, Ender's sister Valentine was conceived because The Fleet thinks the family's firstborn Peter is too cruel and feels the family genius can flourish better in a female child. However, Valentine goes to the other extreme so the family is encouraged to conceive Ender.