Lack of character development?
Make sure you're playing a character with high intelligence, charisma, and wisdom. Dak'kon's plot is tied to the Unbroken Circle of Zerthimon as well as flashbacks dealing with the 'practical incarnation.' (there's a fun little 'sidequest' where you can track down what happened to one of your previous companions, Xachariah)
As for Morte... don't trust the skull. Some major character development is around the corner which explains his loyalty (or lackthereof).
As for answering Ravel's question, there's plenty of ways to answer it depending on how you play. (nothing, love, belief, etc.)
Ignus as a character is pretty basic, but once again if you've dug around enough you know why he's with you.
You're the master who abused him, leading him to seek more and more power which in the end killed him.
As for Fall-from-Grace, she's the only one who truly remains a mystery, but there's some little events that shed more light on her.
Torment's character development is about digging in deep and piecing things together as none of them will spill their guts out in normal circumstances. (which is a bit better than being an emotional crutch)
Seriously though my first playthrough left a "good but... there's room for improvement" impression. I went through the game again and discovered tons and tons of new content and ways of doing things, which then answered more questions about your companions and new ways of ending the game. Then it turned into being a more satisfying experience.