Good, it seems you are making progress. I did not mention before but you can use the very same pinch test on the high speed needle also. Just give the fuel line a slight pinch at wide open throttle and see what it does. It should either slightly raise in rpm or there will be no change when set properly rich for flight. If the engine sags or dies it is lean. Also, make sure your prop is balanced. Do not trust the manufacturer. Get an inexpensive finger balancer. They only cost a couple of dollars and work well for balancing. If the prop is not balanced it can cause the fuel to foam which can cause the engine to die inflight.

One more thing when you are removing the heater from your glowplug. If the idle of the engine drops quite abit it could be a sign of a plug going bad. Might want to replace the plug.