Damn man, you're not having any luck with this!! Don't know if you flipped your reeds yet but did you try swapping the cages from one side to the other when you pulled and checked them? When I got a circle clip stuck in my cage (ironically it was the left side) it did the same exact thing yours is doing. I'm not saying that you have something stuck in the reed, but that gap between the reed petal and the cage can definitely cause issues. The gap from the clip stuck in my cage was a little less than the diameter of a dime and it caused it to run like shit...and when I pulled my plug it had unburnt fuel on it as well, simply because the reed being stuck open dumped too much fuel in the cylinder causing it to misfire. When you rev it up, does the misfire sound like it's going away or is it constant through the RPM range? I really don't think your gas is the problem.
Just trying to throw some ideas out there to stir up some thoughts