Sounds like you have a lot of stuff covered. Some standard mods are a 15 tooth front sprocket to get you a little more top end if you think you will be doing any highway riding. I think it's geared pretty good stock but some like a little more top speed. You will lose a little low speed if you're concerned about that. Also while the back tire is adequate for trail use the front is some what lacking. There is a thread somewhere about what is good, bad and ugly. I myself am getting a Pirelli MT 21, 140/80 - 18 for the front. Pirelli MT 21 Rallycross Rear Tire - Motorcycle Superstore. I am in the process of trying to get a Duro Power Grip mounted up on the rear.
As far as your carb the only way to know for sure if it needs some help is to take a look at it. You can kind of inspect it with out having to remove it. Take the seat, tank, and throttle cables off and loosen the clamps on the in and out boots of the carb. Then you can rotate the top out to the right side and get at the float bowl screws from the left and get at the top of the carb from the right. Take that off and look inside and that will give you an idea of whether it needs a full fledged cleaning. If it don't look too bad and seems to be starting and running fine I would just go get a can of Sea Foam and put about a quarter can in a five gallon jug of good fresh gasoline and run that through it for the next couple of weeks.