I have a few questions regarding etiquette at card rooms:

1. What is the customary amount to tip a dealer if:

You win a showdown?
You win because your opponents muck preflop?
You win because your opponents muck postflop?

2. If one or more players are tipping out $20 or 50 to the dealers (1/2 NL tables) as they leave, is it expected that all players will?

3. Is it considered universally rude to leave a table after winning a big hand?

4. Is it customary to announce "I'm going to be leaving at such-and-such time" or "after one more orbit" etc?

Thanks!