I would get a good 2 cycle engine oil that is NOT all synthetic. The reason for this is because all synthetic oil is to slick and it takes the rings longer to seat. Use an oil that is petroleum based (blend of synthetic and petroleum is ok). The best oil I have found is Lawnboy ashless, it is a good oil and will let the rings seat within 2 gallons.

As far as throttle control and how hard you should/shouldn't run the engine. I know that when I use a new chainsaw or weedeater for the first time, I NEVER run the engine at half throttle. I always break my gas engines in by never setting the high speed needle lean and I always vary the engine throttle. Never do I idle around nor do I run wide open for more than 20 seconds at a time. Once I have about 1-2 gallons thru the engine, I switch to Amsoil 100% synthetic and run it like I want to.

just my .02 cents worth, as I have been running 2 cycle gas engines for many years and never have I had one give me problems. And btw, my weedeater is 15 years old and never misses a beat. It gets fed leftover rc gas.