A little of both. He was able to deduce the fact that Nagato was capable of using the techniques of 6POP but the next min he tries to Rasengan him. He's just irrational at times but he'll figure something out in a fight if you give him enough time, which is why he always fight with Shadow Clones.
Both. You see him progress (especially when it comes to battle) throughout the series, but he still has a certain amount of hardheadedness (yup, I just made that a word.)