Is the FFXIV story basically the PURGE?

[BillyKaplan]

What kind of actions promote Light?

Both us as WoL and the WoDs slayed Ravana. When we did it it promoted Light, when they did it it promoted Darkness. It's like I said before, it's a matter of association. We're Hydaelyn's Champions, the Ascians are Zodiark's. People are over complicating this.

Plus, they became WoDs out of desperation

Which should at least be proof that the Light can be evil, too. It destroyed their world.

and were prepared to engage in some pretty evil acts to save their world.

They weren't going to do anything we haven't already done, the difference was in narrative. Fight people? Kill people, even? Been there, done that. The rest is a trick of the narrative and some lazy writing with how they behaved, though as you said, they were desperate and exhausted, so I'm willing to give them that. Also there's an interesting case to be made here where the Ascians, while for their own ends, were willing to help them while Hydaelyn did nothing until we basically handed the WoD to her, and even then it was more for self preservation (sucking the Light out) than to help her former champions.

Does this mean both the Light and Dark are crummy more so than both can be either? So far, yeah, but Light not being all good is enough breaking the dichotomy for me.

why didn't we just allign ourselves with the warriors of darkness.

To be fair, most of the characters were in the dark, and were faced with the reality that the WoDs were out for blood. You're forgetting that someone did align himself with them, and solved their predicament without falling into the Ascians' hands to boot - Urianger.

How do we stop being so good that we ruin our world like they did.

They didn't ruin their world because they were good. They ruined their world because they were uncontested champions of Light, just like how the Void was born because the Darkness was too strong in it. It's all about strength, and who you represent.

I guess I'm just really confused on what the point of the light vs dark balance if there's no good way for it to work.

Well that's kind of the long lasting plot points so far, with the Ascians harping on and on about how we'd eventually see things their way, and all our scholars trying to find alternatives. That question isn't meant to have an answer yet.

I feel like the story is messed up.

Welcome to Final Fantasy.