I think classes and jobs coexisting is just muddling the water's for SE and creates way too many headaches down the road in terms of balance. This is Final Fantasy take pride in the job system SE and embrace it!

I like the suggestion that classes should become jobs at level 30. Perhaps they can make the opening job quest much like Limit Break In FFXI where in order to progress your experience further you need to complete the first job quest. Once you have access to the soul you can continue on your way to 50. This creates a minor roadblock for players which would help with the leveling is too fast complaints while simultaneously not being as back-breaking as FFXI's limit breaks were and could be done within an hour or two.

Lore wise you can fit it into 2.0 as the jobs now being readily known which leads adventures to take up the classes in the hopes that they can surpass the barrier needed to become a job, which would be the level 30 quest.

Seriously if SE came out tomorrow and said they were ditching classes at 30 in favor of jobs there would be only minor complaints. Also it helps new players because it doesn't muddle the waters. Coming into this game and having to deal with classes and jobs and which to use and when is a major pain in the butt for new players.