what i did was: XP extreme heli (15%nitro 14% oil) and "watered it down" (added about 32.5% methanol to the glow fuel)with methanol, and when mixed 2:1 with gasoline, i got a final result of: 3.1% oil, 3.3% nitro, 26.8% methanol, 66.8% gasoline. it seems to work fine, b/c my engine runs really well and is still running. A few hundred posts back someone stated that the reccommended mix using (10-10) was a bit heavy on the oil, so i opted to use this one. my ryobi was designed to run on 40:1 wich is about 2.5% oil content, so it should be ok in the long run.
as far as the glow plug problem, use a wheel collar to hold the wire on, but make sure it doesnt short out on the plug body.
and did you try a hotter plug? i use a hangar 9 4cycle plug with no problems