Charisma doesn’t help rouges in combat at all so it’s probably a waste to put more than a couple of points there.
True, but this game is much, much more than simple combat; you overlooked passive/direct skills and how much they also impact gameplay, so if you're only in this game for the battles, then you'll be missing out on a large chunk of what the game offers!
However, that said, you can use Wyll's charisma to help with social checks, you'll just have to take the spotlight away from your main character to do it.
For me, all of my characters have high charisma, and dex, as I want to be deadly from both upfront and afar, finesse dual wielder, and ranged for the win!
