Even FFXI looks like it had better characters and stories.
FFXI had the best characters and stories I have ever seen in my 25 years of gaming carreer (excluding, maybe, Mass Effect and Silent Hill), so it's not really comparable. And yeah, if you read carefully last part of main story, it's pretty clear Gaius was not only a honorable man, but also his actions, was he succeed, would actually save and evolve planet. So, yeah, I would sign for an empire in a heart beat.