Just copy/paste :
-blm kit on whm with cure/glare instead of ice/fire
-rdm gauge on sge with shield/dps instead of light/dark
-smn summon rotation on sch (with fairies with regen/shield/dpsbuff/mitig specs)
-ast is already busy, so possibly rdm dualcast could help them
Healers jobs that feels differents -even if they basicaly keep the same healing tools- and possibly rewarding gameplay.
A few dps spells to add but not that much bloat compared to the caster dps jobs, just have a few [o]gcd heals stay instead of some dps tools.
Have the ressources go to skills like assize/pneuma so even burst phase doesn't make people feels like they're in too much danger.