Good! because I always have to stop and think before using Rank and SP as terms for Level and Exp. I am being serious right now lol, it's so much more intuitive the terms level and exp.
On to the topic, I think the "job" titles will just modify your gameplay and abilities so that you are more proefficient in certain areas at the cost of other, but thats just my speculation. Also, I doubt they will be unlockable only at rank 50 since they are releasing a rank 30 dungeons... would be sad to not have access to party jobs then.
I will also add that I would have like them to be completely seperate and have to level them like you had in FFXI, but apparently that is not the case so no use to say much about it![]()