I don't feel like reading through all of these pages... skip!

The Empire fits the Knight Templar trope almost to a T. Their initial cause of wanting to rid the world of Primals (and the Ascians if I'm remembering my 1.0 lore correctly) is all well and good, but the horrible ways they go about trying to achieve their goal isn't acceptable. This request is also assuming the Empire would even want an "ally". They don't want allies, they want subjects. They've always taken a hardlined "conform or die" approach and it doesn't seem like Varis zos Galvus will be changing that stance any time soon.

If we did join them we would be forced to join their military, our characters as the Warrior of Light would probably be executed for possessing the Echo (our "gift" makes us just as bad as the Beastmen as far as they're concerned), and I don't remember the Empire being very kind to the non-Garlean races under their rule so I don't imagine anyone else who wasn't killed would be treated very well even if they submitted without a fight.

Yeah, I think I could do without joining the Empire in any capacity.