Yes, it's inconsistent from book to book and even scene to scene. When I started thinking about this it made me feel a little better about some of the awkward POV shifts in my own writing. Sometimes there's no way to tell the story except by getting into the character's head -- Shasta spends a lot of HHB alone, for example, and Eustace can't talk while he's a dragon. But the more I try to make generalizations about his use of POV, the more exceptions I come up with...

I was never fond of Caspian as a character, but I always thought it might be because for some reason, when I first read the series, I read VoDT before I read PC. In fact, I think I may have read VoDT several times before getting around to PC. I have a vague memory that our copy of PC was missing or falling apart. But yes, Caspian does love throwing his weight around, doesn't he? Even in a good cause, like combatting slavery, it's unpleasant.