Gaius as a lead character? Yes please!
He's the most underutilized character, at least in this game. Well, that's selling him a bit short - he's utilized in a great way up until chapter 3, where he reaches his apex of character development/purpose and then kind of... exists for the rest of the game.
Yeah, I loved him up to that point. And not that I don't still love him, but unfortunately he's just there, sometimes mentioning the wind but that's it. He also becomes less useful as other characters get better and have more useful crafts (though he's still strong).
And yes Insight is a very good status. I always wondered how Gaius was so evasive but it's because his master quarts granted him that status from the start. Alisa's craft that gives insight is also very useful as a result.