No after Voldemort died there was no dark lord. Draco becoming a dark lord tends to happen in roleplaying and fan fiction.
She visited him to see if he knew what the Dark Lord wanted her son Draco to do && if the Dark Lord wanted Snape to carry on the task if Draco failed also she wanted Snape to make the Unbreakable Vow && help Draco so he would not be hurt.
Harry. Draco wasn't even in the room
Voldemort? or maybe Draco Malfoy.
Draco Malfoy is the antagonist in ALL the Harry Potter books. He just likes to cause trouble, thinks he's the best, and absolutely loaths Harry and his friends. He is in a family that is involved with the Dark Arts and in league with the most feared wizard of all, Lord Voldemort.
It was a deleted scene, and I think he was trying to impress his parents.
Lucius Malfoy was given the task of getting the prophecy, and instead it was smashed.
Teacher salaries are unknown.
Yes. He was given an assignment by Lord Voldemort, and Voldemort stayed at Malfoy Manor, his home.
One of his rivals is Draco Malfoy, and two of his friends. His only real rival, I believe, is Draco Malfoy. I'm not quite sure about the two friends mentioned above since I have no idea who those are supposed to be.
For Harry to have become friends with Draco, he would have to have had a different personality before they even met as Harry isn't the type of person who would have stood by and let Draco bully people nor would he have been okay with blood prejudice or supporting Lord Voldemort. Harry would have to be selfish and uncaring to be friends with Draco.
Tom Marvolo Riddle, and in a way, himself, he must defeat his greed/urge to become master of the 3 Hallows, which they nearly destroy some of his relationships. He is also in reality a living horcuxe, which poses a threat also.
He fought for Lord Voldemort in the Battle of Hogwarts, but changes sides during the battle along with Draco Malfoy, and his wife, Narcissa Malfoy. After the battle, he lived a normal life as Harry Potter vouched that they had changed sides and kept them out of Azkaban as Narcissa had saved his life.