I'm going to say that intelligence isn't knowledge just how smart/fast they (should) learn and understand. I look at is as just being 'how well their brains work and how well they learn'.
What it actually contributes though to being a good pitwall driver or staff member, that I don't know
I thought intelligent drivers would be a good thing. But they are aware of their powerposition, so in the long run they are tough negotiators and probably more costly, correct?
I would say neutral. Even if he's in a really bad situation, he could still ask for ridiculous prices. On the long term it will be mostly positive if they are intelligent, as it will help with other things in the game that will have a positive outcome.
No, not necessarily. A dumb driver might keep sticking to his/her demands, while a smart guy might lower his/her demands. The intelligent person just knows their position much better.