RE: prop balencing?
You can buy a device - probably about $5 - that clamps the prop between two beveled nuts on a threaded shaft. Then you hold this between your thumb and finger and see if one blade is heavier than the other. Then you sand a little material from the heavy side. Or you paint the light side with a little clear paint. Or CA glue.
Quite frankly, on a 10x6 manufactured prop, it is probably balanced good enough to just go ahead and fly it. Sometimes props are not balanced from the factory, but in my experience, most of the time they are very close.