I have an idea. The lore could be that chemist was designed to surpass to the limitations of those who cannot use magic, but have a want to be a proper medic in the realm. The role abilities would be explained away by a simple lore explanation. They can in fact perform Esuna, and other minor spells, with the exception of Swiftcast, and Surecast. All they'd have to do is give them something that do the same things like they used to do before the role section of abilities were streamlined.
Which is actually a problem the devs wrote themselves into. At one point each job at unique variations of spells such as Esuna.. which opened up each job being very unique in how they find the means to perform the same effects as other healers.. by removing these and streamlining them, the devs actually wrote themselves into a box that made it hard to create non magic based healing jobs..
I propose that they go back to jobs having unique versions of these abilities again, or that they remove the role actions.. however that might make the game more confusing..
So here is yet another suggestion..
Have Esuna renamed: Esuna Kit. When it is used a powder ball is thrown at the ally, or on yourself, and you are instantly cured of a negative status effect.
Have Repose renamed: Repose Kit. The enemy that is effected has a powder ball thrown at it, that instantly puts it to sleep.
Surecast could just be called Sure-Kit. Though the name kinda sucks. It might have to be slightly different than the swift kit Idea I have below. Perhaps.. Quick-kit.
Swiftcast could be called Swift-kit
Rescue could be called: Rescue-Kit. Perhaps instead of magic, you simple drag the ally back with some kind of a hookshot or a rope.
Lucid Dreaming wouldn't need to be renamed. It is just a simple recharge button.
It wouldn't be that hard. If they are concerned about people getting confused, then they can put a notice under the role section that explains the reason for the change of names, and that they are the same as other healers..
Personally I want all the unique animations that healers used to have, even if they still use the same names for the spells. Astrologians Esuna should be yellow like the stars, White Mages should be blue, Scholars should be green, and I guess sage could probably be another variation of the blue theme it has. Maybe even purple. The uniqueness that these jobs used to have with these abilities used to have such a neat flavor. I'm sad that they are gone, when they really didn't have to be at least in animation.