OOoh, oooh. let's get started.
Caius' motivation makes no sense whatsoever. He waits until the last incarnation of Yeul is dead and then decides to try and release some chaos or some shit to annihilate all of reality in order to prevent her from dying over and over. She's already dead for the last time!! There are literally two humans left in the universe: Caius and Noel. Where do babies even come from in this nonsensical clusterfuck of a universe?
If you can hold off for a few months, we can have this discussion in earnest :).
Add me to the list of FFXIII supporters; however, I classify original XIII as the worst of the trilogy. I'm not saying it's a complete piece of trash--as it established many of the story and gameplay ideas that I enjoyed throughout the series--but it has some clear problems: an extremely boring lead-up period to true character development freedom, some of the laziest side content I've ever seen, and a fairly bland world to explore. It took my recent playthrough (with the PC version) to realize just how thinly designed some of the areas outside of the combat system are.
I still haven't replayed LR yet (waiting for PC version), but I stand by that one as being my favorite simply because it never should have been as good as it was. All of its haphazardly slapped together elements manage to come together into something fantastic and memorable, a perfect melding of the two. Because I've only played it once, I have a hard time defining exactly what makes it stand out more than its predecessors, but it became one of my favorite JRPGs to date after I finished it.
Finally, to wrap up my lengthy post, I noticed you say that you didn't see a reason to micromanage abilities in XIII. There are a couple good reasons for doing this. First, by casting a spell you know a boss/enemy is weak to, you can get the AI to autocast it much faster (as it learns that the enemy is weak immediately). Second, the optional content can get a good deal harder than the main story. You really need to cast buffs manually to ensure they go up in particular orders or time your attacks to ensure success. It's not necessary for 90% of the game, but it can really help in that other 10%.
I feel like I sort of tarred my experience with Lightning Returns by breaking it so thoroughly that I was finished the main quest by the end of day 3. In some ways, it's a really interesting game to me because of that mechanical flexibility, but I probably should have seen what I was doing to my experience and backed off. Many of my qualms with XIII-2 carry over to it -- the combat's somewhat unbalanced, the production values are pretty rough in places, and the story gets kind of unhinged (also, the soundtrack is amazing). I want to go back and replay XIII-2 and Lighting Returns -- I feel like I might be undeservedly lukewarm on them.
I'm sure you're right about autocast. I didn't get very deep into the optional bosses the first time around, and I see what you're saying about teaching the AI teammates the weaknesses right at the beginning of the fight. I believe I caught onto the latter during my first playthrough.