Assume nothing about how mag switches are wired. Consult the maintainer of your plane for an authoritative explanation of the wiring, or otherwise understand it with no doubt.
Generally correct, the engine will not burst to a high power setting upon starting, but is rare cases it can happen, and has happened to me while hand propping - 1800 RPM as soon as it caught. I had set the throttle, but I had failed to assure its correct setting by cycling it through idle to full open to idle again before setting it. My mistake, and I learned from it. This was a mechanical failure of a very old style throttle linkage, but it happened.
I always wrap my four fingers around the trailing edge of the prop. If others can safely handprop by finger friction on the back of the blade only, success to them, I could not safely accomplish this technique. As I stated earlier in this thread, I do not handprop engines I do not "know" - either because I have electric started them before, and know them to have decent starting characteristics, or it is the engine of a trusted friend - who themselves would handprop it. I do not wear gloves while handpropping.
I have never had a kickback while handpropping ('not saying it can't happen, but it's never happened to me). A hearty swing on a properly timed prop, carries it through forward well. My experience tells me that a good hand swing can get more starting effort into a prop than some starter arrangements.