Hm... I think perhaps there are fewer inconsistencies as you say in CS2, but they are more disconcerting because of the plot. It's extremely unusual to see a self-doubting person suddenly become a hotshot daredevil leader, and the number of times Rean seems to change his attitude depending on the villain he is facing is hard to understand. The V example is the most egregious, but showing excessive amounts of mercy or politeness to people who have no business receiving either is bad form throughout the game. Claiming to be independent, yet being anything but, is more plot-wide of a problem but Rean is the progenitor of that issue.
Oh, I definitely feel you on the self-doubt thing. When it's done well, it can be a really effective way of getting the player to connect to a character (see: Joshua, Kevin, even Estelle, etc). But when it isn't... well, it just becomes lip service. And for most of CS1, that pretty much applied Rean. Never feeling like you're good enough for your friends and family is relatable on paper, but Rean is such an extraordinary person, it almost feels facetious. To put it another way, I can fully understand why (3rd)
Kevin feels like a complete loser despite being one of the most powerful characters in the setting
That said, CS2 is far better about this in regards to Rean's character. For one, Rean actually manages to curb his self-doubt in this game. In the
intermission, where instead of tripping over himself to praise his opponent, he bluntly tells Duvalie and Bleublanc that the difference between them isn't high, and proudly announces himself as a practioner of the Eight Leaves style before taking them on. This is in stark contrast to how he's usually like. He tells Crow, the guy who's been kicking his ass constantly that he'll win. He's also confidant about taking out Lloyd and Rixia, though that doesn't go as planned, haha. There's a clear, discernible difference here.
There's another fundamental difference between CS1 Rean and CS2 Rean that makes the latter better. In CS2, Rean is allowed to fail. He fails constantly. He
loses to Crow, and is forced to board the Pantagruel. He's unable to protect his home from getting torched, or prevent the princess and his sister from being kidnapped. He causes Vulcan's death. He fails to bring Crow back. His mission in the epilogue is a wash. The war ends, and he ends up becoming Osborne's puppet.
For CS3, I'm much more interested because Rean's setting has greatly changed and he's now in a role where his personality can shine in a more clear cut way, and also thanks to CS2's divertissement and ending where Falcom set him on a much more tightly defined course of actual self-conflict that I think they were trying to aim for in the Cold Steel series up to this point.
Also, and this is a big one, I honestly can't think of another JRPG where the main character is a (military) teacher who must lead his students; anyone is free to correct me. I think the idea is a unique, fun, and interesting one. Lots of potential for moments that you don't really see in JRPGs nowadays, and we can see hints of these moments in the CS3 trailer.
A-fucking-men. His body language alone conveys a HUGE departure from what he was like before. Getting to play as a grown ass instructor with a full-time job as a military officer has me immensely excited. And you just know they'll spit the focus between him and his students, which should make for some interesting scenarios.
Also he can also drink now! With Sara!!