There is a parallel discussion on a secondary class for a character.
However, I'd rather prefer a profession for offering additional skills and/or passives.
Ideally I would like to have this as a skill tree rather than what we now have with the skills that just unlock with increased skill level and where you only decide on morphs. This approach of skill development for me has a shallow feel upon it and removes the sensation of character development with growing experience which imho is so essential for role play games. And which I really miss here.
As I guess we will never have a more classical skill tree allowing a real character development this profession could give us at least on this a sort of character growing experience.