Interesting argument about the exit row seats but fairly irrelevent, these seats are for fare paying passengers so, by definition, anyone sitting there requires no special skills other than being able bodied.
As for the meaning of a 'Profession' my definition would be a career or post that requires a professional qualification ,so that would exclude cabin crew, though I don't think they would claim that their job is part of a 'profession' That said doing your job professionally is a definition that can be applied to any type of post, and most people would aspire to that. Strictly speaking I suppose that flight deck crew do not possess a professional qualification as such.