I picked up the game in the spring and since I work close to AC I started going down once a month for the heck of it in September. (Been profitable, too.) I know how you feel - you don't want to make a fool of yourself out of ignorance but you know what you are doing in the game itself. Don't be so worried, I guarantee you that you'll witness people being dumber than you could ever manage.

You have the tells part dead on. Make looking at your hole cards and your betting actions habitual and repetetive, whether you have AA or 72. Otherwise don't get yourself distracted too much with tells and play your game. You'll know when you are comfortable enough to add that to your task list on each hand.

Take a deep breath before you make action if you feel shaky hands syndrome. I guarantee you won't be able to control it on the first pot you think you are winning, but it'll become more comfortable after that.

DON'T STARE AT THE FLOP WHEN IT COMES. Look at the other player's reactions first, then check the cards. They aren't changing so there is no hurry to look at them.

I've got no advice on changing limits as I am solely a tournament player. I'd figure you want to stay at whatever stakes you are winning at and just keep winning, but that's just me.

Listen to the dealer. If you breach the rules of conduct they'll make sure you know. You are pretty much given two chances: one is a soft warning and the next is stern. As long as you heed the soft warning, nobody will have any problem with you. If you don't heed the stern warning, you have trouble.