I will take a stab at a couple of questions...
1) I look at it mostly as a knowledge database and how pilots feel about their jobs and how the airlines are doing.
2) at least 3 times a day
3) Reading forums and looking at airline profiles. I like to read the flight training, photos, sections mostly.
5) I have read some excellent threads here that has much value to student pilots and the pros. I think if there was a compilation of those threads it would not only be a great refresher but also a great learning tool.