Nice looking bike.
1) Looks lean or dry (less oil in the premix) in my opinion. If you are not mixing sufficient oil to the fuel it can look leaner than it is, but I still think you are a bit lean.
2) Oil around the plug is from it weeping, that temp gauge pickup has work hardened and is not working as a good seal anymore.
3) Check your cable, no throttle the slide should be really close to closed (but not quite closed maybe 1mm-ish lifted from the floor) and wide open should be with the bottom of the slide level to the roof of the carb bore. Any higher will cause turbulence above the main jet and can cause stumbling at WOT
4) lube the cables well, same for the controls. If there is too much slop before the brakes even work then adjust by oozing the knarp and pull through more cable then tight it again, use the cable adjusters to fine tune. On the throttle use the adjuster to fine tune if there is slack in the carb cable, but only if there is slack. If there is binding, lube where it needs or replace the cable.
5) Unless it is close to winter, your choke should only be for just getting the cold engine to catch and run. On a two stroke if the choke is needed for an extended period there is something not correct and you need to do a tune up o the engine.
Hope some of that helps