Tire rubbing the frame/chain? Yeah, I had that problem too, tracked it down to the axle shifting around in the dropouts. I ended up using banjo bolts to lock in the axle. However, my frame is a Skyhawk GT2 with reverse dropouts (axle slides out horizontally to the rear to exit) where most bikes use 'Forward' dropouts (axle slides diagonally forwards & down to exit). I don't know how your frame is set up, if you have the forwards style, banjos may not work for you. But for the sake of argument, here's what they look like & where to get them online in case your local bike shop doesn't/can't get them.
I'd recommend a spark plug upgrade, the tri-prong radial plugs that come with these kits are junk, go with NGK B6HS or BP6HS (BP is a flat seat & comes with a ring gasket, B is acorn style seat, no gasket), maybe heat range 7 if it runs hot (it'll ping on cheap gas). DON'T use the Champion L86C! It will overheat, mine did & it warped the head! Next up is the plug wire; I ripped my wire out of my coil, (some of them are glued in & need you to dig out the junk with a wire pick before installing the new wire) & I used an MSD plug wire left over from a tune up I gave my truck. Even a used wire from a car is better than the new wires in our kits. Cut to length (about a foot) & strip off 1/2" of insulation cover, slide on an inch of shrink wrap tubing & thread into the coil(the contact pin is a spring style pigtail screw). Once it's in as deep as you can get it, slide the heatshrink over the end, heat it with a lighter and you'll have a watertight connection that can be serviced again if the wire needs replacing. Silicon could be used too, but I think heatshrink is cleaner & looks more professional.
Last up, go to the link below & download both Gordon Jenning's 2Stroke Tuner's Handbook, and Graham Bell's Performance Tuning. Knowledge is the most powerful upgrade you can get and cannot be understated. Even better, they are free downloads. Read it. Learn it. Do it. Be awesome.