Showing my support for Geomancer again. But this time I want to give an idea of how they could make Geomancer a tank. We know they can't/won't add a dps class in 5.0 and Geomancer healer makes no sense with Whm there.

My idea is simple, make it a close range caster tank. Nothing wrong with casting spells on enemy's face if they're a tank to begin with. We saw what Geomancer's primary role was in the AST story and it's clear they're protectors. What describes the tank role? Protector. So it could be that when the stormblood geomancers unlock more of their magic they could eventually become those real protectors and be tanks. It's all clearly laid out in the AST story. They're not healing, they're doing minor damage to enemies, but what are they really doing? Shielding and protecting things against damage.

So that's my idea/theory behind Geomancer tank. You're basically casting natural barriers using nature to tank the damage from enemies.
I tried, overall I really Kazrah's views on a lot of jobs and how they could work. Specially the Green mage tank idea