New traveler going on Cathay for the very first time on business class.

Hey Guys,

Like many of you guys out there, I have signed up for 150k in miles from AA promo.

I will be going from SFO –stopping by Hong Kong – and finally landing in Seoul Korea (ICN).

Since it’s my very first time using Cathay I just had a few questions.

1. Since I booked using miles, can Cathay downgrade me from business class at anytime?
2. Do the stewardess know that you’re on there via miles?
3. Can I check in online?
4. I will be leaving at 1:20am. What time should I show up at the airport?
Also does cathay charge for checking in baggage?

5. Does SFO have a lounge for business class?
6. Are the bathrooms roomier on business class?
7. Upper deck is usually better for business class?

Sorry for so many questions! Im anxious and excited at the same time! 

Thanks in advance!