Like others here I believe kids need a bit of slack rather than a taut leash.
My friends kids are the closest thing I'll have to kids of my own. (Known them their whole lives.) I lived with them for most of their lives. One could even say I had rather large part in raising them.
We, their parents and I, grandma/grandpa to, never really hid anything from them. They had to learn at an early age what a junky, and dirty needles were. We lived on a street that had a couple different crack shacks come and go over the years. They needed to know that needles were dangerous and to never touch them. They knew and understood about drug addiction by the age of 5. Kids are not dumb.
They play Skyrim, Fallout:NV, Fallout 3, God of War, the Fable series. They are very well balanced, kind kids, and very intelligent for their age. They are 8 and 10 currently.
I'd let my kid/s play if I had kids. I know we all have our own views on parenting though. I just think Skyrim is
pretty tame in the end. Not worth the concern of an M rating.