My friend is an extraordinarily good artist. Extremely talented. He's been an artist all his life, and would like to use his artistic capability to support himself financially.

He's looking to try and do the following things:
Making High-Definition highly detailed characters (Drawn and in 3d)
Drawing (Incredible drawing of anything)
Self-Inspired 3d Animation Short's (all self-inspired, maybe could be used as intros)
Making Art for a Video Game (Characters, Structures, etc)

He's worked with studio's before and the biggest problem he has is, working for a company it limits his creativity, instead of creating, he just fills in the missing spaces with fancy graphics. So..

Could any of his talent, be used to maybe create a studio, and would people be interested in purchasing, his self-inspired work?

Of course. There are lots of artists offering their work - you can order a printed copy of a drawing/photo for example and have it sent to your address.
He should build an online portfolio, so people can see his works.

I may be interested in his services in the future. Does he have a portfolio.

he's made amazing websites in the past, he just doesn't like the business aspect of it, being confined with what he can and can't do. Can he make money off doing these things?