I think healing would be a lot more interesting if they reworked every of its class to have 60% healing/buff abilities and 40% Damage abilities. Right now its pretty much 90%/10% in their toolkit and certain big heal abilities rarely get used in normal content unless you're like me and use them even when its not completely necessary because you feel like its a waste having it go unused. Here, I'll pick some healing abilities that could just be either cut or reworked to instead be a dps skill.

Sage - Drouchole: Not needed because Taurochole does the same thing just stronger and adds a buff to boot. Replace Drouchole instead as an Addersgall DPS button or better yet another DOT
- Diagnosis: Not needed because almost always you'd want to use Eukrasian Diagnosis for the shield effect anyway. Instead make Diagnosis a spell combo for Dosis. Now we have a 1,2 rather than just 1,1,1,1

White Mage - Cure I: Have this get upgraded to Cure II rather than keeping them separated because nobody casts Cure I for the free Cure II proc, its an unnecessary trait. Instead, convert this into a spell combo for Stone/Glare.
Cure III: In my experience I rarely use this as its too MP heavy and Medica I is a more efficient AoE heal anyway. Convert this button into an AoE spell combo for Holy that applies a DoT to all enemies.
Assize: Give us 3 stacks of this so that we can get some more extra damage in as well as better means to give some MP back as a White Mage.

Just a couple of ideas of mine thrown here, but I feel that already this changes up the dps monotony of these two classes a lot.