She absolutely is. She's looking for deifacted nethicite so she can blow away the Empire. The game shows us what nethicite can do to people (a portion of the Empire's entire fleet is destroyed instanteously), and we are TOLD what it did historically with Raithwall. The very climax of her character arc is her realization that she doesn't want to be Raithwall and doesn't want to be manipulated by the Occuria.
I've said this before, and I do believe it's true-- FFXII is a much, much meatier game than any previous Final Fantasy. The dungeons are massive. FFXII's main script (not counting ancillary dialogue, the bestiary, etc) might be thinner than FFX's, but because you're going to be spelunking in dungeons for 3 hours at a time, the pace of exposition feels much slower and therefore the player feels much less of it. There's a huge chunk of time-- the walk to Archades is my favorite example-- where very little "happens" in an expository sense. I mean, a ton happens from a gameplay sense and you see a ton of beautiful things and listen to amazing music-- but this isn't at all like FFX. Seriously, how many times in FFX do you get stopped on the freaking linear Mi'hen Highroad?
I LOVE both FFX and FFXII. They are genuinely wonderful games aiming for different things. I'm still able to hold in my head the idea that FFXII's story is not as fully developed or as proudly delivered as implied in the first 5-10 hours of the game...from the rush to save Raminas to Vayne's the-game-you-like-will-never-touch-this-game-ever-and-don't-even-argue speech in Rabanstre...while still thinking it's a highly satisfying tale that at very WORST loses focus and becomes pretty standard stuff like in every other FF.