Yes, Sandstorm is Firestar's mate and their kits are Leafpool and Squirrelflight.
Yes, he died in The Last Hope.
You don't ever really find out, until the eggs hatch, or not hatch in the spring. Because, even if she has not mated, she will still lay eggs.
Firestar is not yet dead, and we do not know who will kill him.
Polar bears have mated with Grizzly bears. http://www.msnbc.msn.com/id/12738644/GT1/8199/
Perhaps in dreams, but otherwise, no. I don't think so
No male duck will ever turn into a female duck.
When Firestar was the kittypet Rusty, ThunderClan was closest to him. He was for their prophecy, and they accepted him into their clan. He didn't ever want to switch his clan, so he couldn't and can't be the leader of them.
No, they live forever. I'm kidding. Yes, of course they die.
Of course. None of the cats will live forever. He will probably die in the series Omen of the Stars.
Well, that's a matter of opinion, so it's up to you to decide.
Louise Rennison was crowned the first ever Queen of Teen in 2008
Mary, the queen of scotts