Honestly, the numbers for averages are accurate but estimating the "above average yet not overpowered/broken" is more difficult than you might think. They are really just estimates at this point, they could be higher/lower. We have played Pathfinder before, but this is our first time GM'ing this engine. There are certain questions that I just can't answer because we've never experienced it ourselves. This is a bit of a learning process for us too, so please bear with the balancing/GM choices we've made and wait until we've gotten some actual gameplay in before over-analyzing what we're working on.

For now, think of building your character this way: Think of your character, ignoring stats, as though they were a real person or a person in a novel/show. What is their personality like? Who is this person? What do you want them to be and what do you want them to do? After you've fully created your character in this way, THEN you adjust your parameters to reflect this person you've made. As the game progresses, build your character even further towards that end goal. It should be that your personality and the character themselves dictate what parameters you invest in, not the other way around.