I think you will find that a new nozzle will make your CS spray much better. Yes, you've trashed it. I know that some people use an old needle to clean their nozzles, but I would never stick anything metal in there. The tip is very thin metal and really easy to damage, especially when .35mm or smaller. A shaved down toothpick used gently is much safer. I doubt whether the CS nozzle is any more fragile than other airbrushes.
The drag on your needle could be due to a build-up of paint in the channel behind the cup. Have a look at this page for an illustration. Get some interdental brushes and swab it out. I would use lacquer thinner or acetone.
If you clean your airbrush right after you use it, you shouldn't have dried paint inside. You don't have to tear it completely apart to do it. Just flush and swab the areas that paint hits and wipe the needle. The HP-CS is very easy to clean.
The sticky trigger is common in Iwatas. There is a rubber O-ring inside the body that the trigger passes through. Iwata recommends applying a little of their lube when it sticks. You need to pull the trigger to do this. Hopefully there is no paint back in this area. I wouldn't mess with the air valve unless you really have to. This page may be of some help.
Don