Your graphs look a lot like the ones I made internally :) Try comparing the `agree_` and `important_` across age ranges / genders, I was able to pull some stats out of those but since the sample sizes are so small I didn't want to release it to the world.
The tl;dr is that yes, there is a positive correlation between developer skill and salary (http://minimaxir.com/img/stack-overflow/so-programming-6.png) for example, but it's hard to say which-causes-which.