Yes , he is. He saves Harry and his friends from the Malfoy Manor but is killled by bellatrix on the way to safety.
No.
Yes he is.
No.
No, Dobby does not return. He gets killed by Bellatrix Lestrange in the Deathly Hallows.
Dobby's age was never mentioned in the series.
Bellatrix Lestrange.
Part 1
he gets stabbed when trying to help harry out and dies
Bellatrix kills him in Harry Potter and the Deathly Hallows
Dobby and Kreacher.
Dobby died in Harry Potter and the Deathly Hallows.
Yes he was nice because he saves Harry in the Deathly Hallows