ZantaClaws, welcome to the wonderful world of MMOs! I'll try to help you out a little bit.
KEYMAPPING
You have your keys bound pretty well. Personally I use ESDF to move because it frees up my pinky to use QAZ and moves my hand over to make TGV available. I'll set A to my most commonly used "free attack" so I can pinky-spam it while moving freely. R+W I set to commonly used special attacks. Most other abilities to QZTGV. Number keys I use for utility like shields, taunts, etc but I do have some missile attacks in there. I like using ALT because my thumb doesn't do much other than press space when I have to jump. I'll set ALT+E to my interrupt (like "moving at them" to punch them lol) and ALT+D to my grappling hook (bounty hunter) to "pull them back". I have most of my big timer utility abilities set to ALT+QWFV keys. Stun I have set to ALT+C because it's easy to hit while chasing someone.
One thing you want to try, if you don't already: hold down the right mouse button and strafe instead of turning with the movement keys. Use the mouse to change direction and look around. I do this basically the entire time because you can always look where you want and keep your target "in front of you" regardless of what direction your feet are moving--or do a complete 180 in a split second. It's great for coming around corners and even while running away (instead of just pressing W [or E in my case] you turn your side to them, hold the right mouse button and press D so you're "strafing away" but they're still in your arc of fire). And yes, for keeping them in front of you while running in crazy circles.
Why people love running in circles
There are a few good reasons to run in circles. It boils down to "stationary = easy target". Here are some reasons why:
It's disorienting for your opponent, trying to track you to fight back
If you move behind them, you are out of their arc of fire--if only for a split second (more hits = you win)
A stationary enemy is easy to hit with a ground targeted AoE [area of effect] or will eat the full force of a channeled AoE
If you're in the middle of a group melee frenzy, if you run around some people won't keep up with you and cut back in time to keep you in range--giving you a chance to avoid some shots and live longer rather than standing there and getting beaten
If you're on a map with ledges and pillars and people are trying to shoot you from far away while you're fighting someone else, if you're running around sometimes the terrain will momentarily block the line of sight
Hopefully this sheds some light or gives you some ideas to make yourself more deadly and your experience more enjoyable!