I was certain that Geomancer was going to be a new Job because of all the lead up and hints in Stormblood. Perhaps next expansion then.

Job Name: Geomancer
Job Weapon: Bell

Geomancers would have a Job gauge that represents the 4 elements: Earth, Fire, Wind and Water.
The gauge would be in a cross formation with Water to the North, Earth to the East, Fire to the South and Wind to the West.

The gameplay of the Geomancer would revolve around gaining points in an element that would unlock new, more powerful spells in that element.
But, gaining points in an element would reduce points in it's opposite element. So, gaining points in Water would reduce points in Fire.
This would allow you to have 2 elements at maximum while the other 2 would be at nothing.

You would spend the points on cooldowns, such as a 30 second cooldown would take 50% total points in an element. Because it would be impossible to 4 of each level of cooldown I was thinking you would press a button for the 30 second cooldown then press one of the low level heal buttons that would be the 4 elements similar to how Dancer's Steps works.

The different elements would specialize in different types of healing. Earth would be absorb shields and Water would be AoE heals.