I'm certainly not as far into it as many here so I'm still in the "Wow, look at that" part of the experience. I would definitely rank it somewhere in the top of the line for both video and audio. Good surround effects and some deep bass coming out of the subwoofer. The world is fantastic so far. You can spend a lot of time just panning around staring at the horizons.
It's tough for me to comment on the kids question. I'm not a parent and all parent's have their own level of comfort with these things.
Yes, you will be killing lots of monsters and lots of people. However, it is a lot less gory and less intense than many games, like say Call of Duty. It is not overly gory or graphic. It will cut to some slow motion kill scenes some times but a spray of blood is about the worst visual it will show.
So far, I haven't hit any foul language but I'm just barely into it. Nothing sexual so far either. Previous titles would have some spoken innuendos and you can strip a dead person down to their underwear if you steal all their armor & clothes as loot.
People deeper in can probably comment better than me.
