No. Riku never dies in Kingdom Hearts II.
No you can't. But if you have the Kingdom Hearts 358/2 Days for DS you can play as Riku in mission mode.
Xehanort, aka Xemnas, dies in kingdom hearts 2 when the player, teamed up with riku, defeats him in the final boss of the game.
Yes, they do find Riku at The World That Never Was.
I don't think you can
Roxas sora and riku of course
You kill xemnas with the help of riku
Oh yeah, he's adorable. Even going up to kingdom hearts 2
At the end of the game in the Land of Darkness, you'll soon meet Riku when he brings Kairi back to you. He'll soon join you to fight and destroy Xemnas. Unfortunately, you can't play as Riku in Kingdom Hearts 2.
In Kingdom Hearts 2 Riku gives Kairi a keyblade and she uses it to help Sora with Riku fighting Heartless in The World That Never Was.
If you really concentrate on it, you can make it happen.
You can't give Riku a keyblade, he just gets it in Kingdom Hearts 1 when he goes in the Door To Darkness. AA: Riku is just a world specific ally so you cant change his weapon
Riku's Birthday is not confirmed. However, his age is. In Kingdom hearts I(1) he is 15 years old. Though in Kingdom Hearts II(2), his age is technically not confirmed. But, since it IS confirmed that it's been a year since the end of Kingdom Hearts I(In Game time), so he's probably around 16.