Allowing for cultural differences...some are used here...
I have found that a lot of the Kid Speak is very similar to our message texting via the Mobile phone...and by adults...
I have heard of some of the Chat Lingo before and most of it I would never use but that is me... when I first went on the net I was "surfing" not knowing that I was and I wandered into a 50's chat room and was asked my ASL and I did not have a clue what they were talking about and was told age/sex/location and IMO I got the impression that they were chatting each other up and swiftly exited the group wondering what the heck I had stumbled into....and NIFOC would probably come up a lot in those sort of groups, unfortunately that & some others were in the list and because of copyright laws the list had to be posted in it's entirety...
I would not use those chat emoticons in a message either but I would use the picture ones that are built in and some other similar ones but I know a lot of people do like using them especially on their phones..