maybe it was mentioned already - but there is a very good chance you'll need one hand to fend off an attacker so how are you going to rack the slide? I always figured the first thing I would need to do is put myself in a position to be able to draw my weapon so that means using my off hand to block, push-off or something. If have time to get to the weapon without there being a wrestling match, I would not want to be having to deal with slides and safeties.
As to weapons around kids, the guns probably safe as long as you have it on you. But once you don't have it where you can control it, I'd keep it with no round in the chamber at a minimum (maybe even keep the magazine out but easily accessible) if it wasn't actually locked up unloaded. With kids if something bad can happen it probably will. They are just too curious. There was a case last year where someone kept a loaded gun in the glove compartment, they left the car with their 2-3 year old in his car seat. The boy got out, got to the glove compartment and shot himself. To me any chance of something like that happening is just not worth it - guns do kill people not just the bad guys with them.