Over the Board Etiquette

I have a few questions about OTB etiquette. I am under the federation of USCF.

1. If you are in time pressure, do you have to write down the moves as you play?
   
   
2. How would you know if your opponent is cheating?
   
   
3. How are you supposed to offer a draw to your opponent?
   
   
4. How would you prepare against your opponent? 

I assume you are talking about slower time controls. You are supposed to keep score. If you don't, it may be hard to claim a time forfeit, or repetition of position.  There are special rules excusing a player in the last five minutes of a non sudden death time control.  (Buy a rule book.)

Don't worry about cheating. Just play your best.

Read the rule book for all the precise instructions von offering a draw. Basically, you are supposed to offer a draw only on your turn, after you move but before you hit your clock.

It is unlikely you will know who your opponent is until just before the round starts. There is no time to prepare.

if its a fast game you don't write down the moves