Lets tackle these two.
First of all "mixing drinks" is the common freshman excuse for getting very drunk quickly and usually throwing up. It comes down to people drinking sugary mixed drinks way too quickly, the sugar messing with them, and other things. I "mixed drinks" walking around the world and during many other times. Beer, liquor, wine, mixed drinks, etc. I was fine because I wasn't crazy gulping them down.
Second, I bet you've done drinking games before. Even if it's not pong, quarters, flip cup, boom, beer die, etc. Ever drink to a movie? Ever drink to a bet? Even a sip? That's a drinking game. I have to know this because I've had to deal with "risk management" through university, fraternities, and other such things for a bit. Drinking games are when a drinking is added to a play element in order to get drunk the fastest. Drinking around the world is not a drinking game.