The problem you're having is deciding whether you want to roleplay or 'rollplay'/metagame. You need to make a decision. If you want to roleplay than the mild bonuses from the dialogue shouldn't matter...view them as natural aptitudes you didn't fully explore. Not everyone becomes an expert in all the things they are naturally talented at. If you want to metagame then...do so?
Why simplify the possibilities because you lack self-control?
You're simplifying and making assumptions. I'm saying the dichotomy doesn't need to be there at all. I and everyone here have the self-control to choose between roleplaying and metagaming. What I think we're arguing is that the dichotomy doesn't need to be there in the first place, and only functions to draw a rift between two play styles that can coexist harmoniously.
If you aren't planning your character out from the beginning then it wouldn't matter. If you are planning your character from the beginning then you already are metagaming and you should just abuse the system because you're already trying to. This concept of 'half roleplaying/half metagaming' is not conducive to a happy life. You will never be satisfied. What happens when you find out certain quests/dialogue choices could give you something that your specific build needed to be the best at what it does later on? Does that mean it should be available to someone who roleplayed the way you chose to?
This isn't an either/or situation. The world isn't divided into people who commit to roleplaying or people who commit to metagaming. There are degrees, and for some people (including, seemingly, half the people who have commented on this thread) somewhat arbitrary stat bonuses have the potential of restricting roleplaying freedom. Expecting people to commit to one or the other is silly/
There's no possible way that you are 'underperforming' in combat because of small trait bonuses. It's far more likely you built a horrible team or are lacking tactical analysis. Or maybe hard isn't for you.
That remains to be seen, doesn't it? Only a small section of the game is currently available, so I'd argue it's not outside the possibility that these stat bonuses can amount to a huge advantage late game. If they ultimately are inconsequential then I suspect most players won't mind one way or another.
