You play as Vader during the game's intro level (or Prologue). You can't play as him after that. However LucasArts is going to release updates for the PS3 and 360 versions and one of the added features is new characters to play as. Perhaps one of them is Vader, but I am not sure.
Darth Vader
The apprentice fights Vader on the Death Star and wounds him.
Its Darth Vader
Darth Vader gives it to you.
no
Level 3 Force Repulse.
umm nah dip Death Star!
in the end you can choose to fight him or the emperor
The Emperor Darth Vader Darth Desolous Darth Phobos And that's all I remember
Darth Vader's "secret apprentice" is called Starkiller.
he didn't, it was a clone made by Darth Vader
Yes, there will be a brand new force unleashed 3 with the story being Boba Fett rescuing Darth Vader from Rebel clutches.