Your rank (ie Group Captain or Air Marshal) and your ranking (ie top 100) are determined by the points you have earned alone. They are not determined by your kills, bombings, etc.
For example if you are the closest to ranking up in your rank group ( you have the most points of all people in your rank) you will be ranked as number 1 for your rank. However, when you do rank up, you will then have the lowest points for your rank and will be the least ranked for your new rank. Confused yet?
The other stats are just a way to see how you are performing personally and what you have done to earned the points that got you to your current rank.
So, in reality, your ranking in the game is really a measure of how much you have played and you can use the stats to determine how you compare to other pilots. What can also be assumed as a rule, is that folks in the higher rankings are more experienced and more skilled. Again that is as a rule. There are some pilots that are more skilled than those ranked above them, but haven't yet earned the points to show it and if they stick with the game, the stats and ranking will eventual catch up with their skills.
Hope this helps,
PH