A popular dubstep artist who likes writing music about aliens and making fun of them. After a concert he is abducted and taken to outer space and has to get back to earth before the aliens kill him.

What's the genre? A mashup of comedy & sci-fi or...?

"What is his flaw?"

He's a dubstep "artist".

"This will make him a unique character."

Unfortunately, no.

This reads like a fairly generic alien abduction movie as most of them involve an alien abducting a human and the human needing to escape to save his or her life.

What is his flaw? This will make him a unique character.

Who is the main alien that wanted him abducted and what makes him so revered? This will make him or her a unique antagonist.

What is the aliens original motivation to abduct him? This will motivate them uniquely and help define his obstacle.

The part in the logline about "A popular dubstep artist who likes writing music about aliens and making fun of them. After a concert..." is redundant and too long instead all you would need is the inciting incident. "After being abducted by aliens a dub step artist must..."

Hope this helps.