Hi Leon,
I can see from your screen shots that you've got everything to the max at the moment. You've got a pretty decent system there that should give really nice results with CLoD.
First of all just check that you are running the latest version of CLoD. You should be showing version 1.05.15950. I'm sure you are, Steam is pretty reliable.
To get a measure of frame rates bring up a quick mission. When its running and you're in cockpit press Q to bring up the console commands. Now type in fps START SHOW and press enter to bring up the ingame frame counter.
When flying, get rid of the mirror immediately. It does nothing at the moment and you will see an immediate gain of 5 - 15 fps, depending on your system.
Now go into the video menu and bring up the options. Have you got trackir btw? Set your resolution to your monitors native resolution and your refresh rate to that of your screen too. Set anti-aliasing to 2. Again, this is another feature that does not work at the moment. Make sure the anti-epilepsy filter is unchecked. Uncheck the SASSOA thingy too. Once again, this is a feature that did work but is now no longer needed. Vysinc? Depends on whether you have trackir. If you have then put it on but it's worth experimenting with.
This is air combat so who gives a shit what the ground looks like? Leave those beautiful shadows on and effects to high but reduce all the ground 'enhancements' to low and then see how you get on. That means land detail to low, building detail and frequency to low, trees to low, roads off, grass off, etc and see how you get on. What would be nice in a future patch would be to have the option to disable ground shadows whilst retaining cockpit shading. Look at all those trees and the blobby shadows they cast. Thats eating up your systems resources for no useful reason.
Fly around and see how smooth you run the game and what fps you are getting and then start turning the effects back up until you reach that compromise between eye candy and game performance that you can live with.
Flying with CEM off will give you better frame rates but once you've got to grips with the basics I'd try and fly with it on as much as possible as online it's mandatory and there is something rather satisfying in having mastered it. Nothing too difficult either it's just that each 'plane has it's own method.
Can't think of too much else at the 'mo as I'm on my lappy not my game machine. Good luck and have fun.