I see where you are going with this, but rather than divide by how often you miss, I multiplied by how many times you hit. Either works. However, I wanted to combine your headshot percentage and accuracy into a single component, your "aim component" as it is solely dependent on your aim. I see you are not wanting to treat headshot percentage the same as accuracy, and I have thought about this; heavy weapons users will not get accuracy bonuses at all if I multiply those values together, and they are entitled to the accuracy bonus. I am really considering your approach to this.
I don't entirely agree with your approach to headshots, however. By multiplying damage by the number of headshots rather than the headshot percentage, you are favoring longer play times. People who play longer may have only 1 headshot per kill, and have 70 headshots over the map, while a person who joined recently may have 2 headshots per kill, but only get 40 headshots total, getting less headshot bonus (Less Damage * Less Headshots) even though he is better at getting them. Shots - Headshots is headshot ratio and accuracy combined, and because accuracy is already accounted for, this should be changed. I guess this was just your attempt at soving problems of 0% accuracy glitching the rate.
I REALLY like this idea. I was trying to think of how to do this and this is a good way to not penalize aggressive players too much.
I may be changing mine again, but I am trying to think of the proper solution to combining the "aim factor" to the damage given. When multiplied, it favors longer play time. If static aim factor, then a value must be determined for it and it would not hold its rate value compared to damage given. Your suggestions may be very helpful in this part Giriel, you have some good ideas. I'll edit this post and add my latest formula after I think about it more. Edit: Actually Giriel, you are close to having it right, I'm going to change a few things, but it will be based off of what you have.