>>3726
Change your connection settings. There are lots of guides out there to help you do this.
Fiddle with your settings until you're getting at least 30 FPS at all times. Any less and your aim will be affected.
Check your mouse settings. You're best off using raw input and no acceleration. As for the sensitivity, that's personal preference.
In combat, never hold down the fire button. Press it once every time you want to fire.
For fighting direct hit soldiers, you have two options.
A: fight them like they're using hitscan and get as close as possible. This doesn't work well on skilled soldiers, but throws off most people.
B: keep enough distance that you can dodge every rocket.