Thunderbolt Display with a New rMBP

I am new using an external display and the rMBP and not very tech savvy, but I did go ahead and purchased a TB Display and a rMBP to replace my home computer set-up which has been a MBP using an ethernet connection for the Internet for the past 6 years. The MBP has had issues for about the past 3 years, but I have managed to get by.

I have some basic questions about a Thunderbold Display and a rMBP I just purchased. Is the Thunderbolt Display connected to the rMBP by way of the Thunderbolt cable or are there several options to connect it to the rMBP? If there are several options is one better than the other? When using another Dsiplay with the rMBP does the rMBP display come on too, so that both the TB and the rMBP displays are both on? is there anyway to have just one (the TB display on) and still be able to use the rMBP computer? (make sense?)

Has anybody read of many problems with the this display when used with a rMBP on the forum?

Since the TB Display has a ethernet port, can I use this for my ethernet cable? For travels I would still need the adaptor to use an ethernet cable with just the rMBP, right?

I am anxious that I have the cables and have some idea what I am doing when they arrive. I felt I needed the external superdrive. Will that need a USB 3.0 to connect it to the rMBP or would I need the USB 2.0?

Any other advice about getting the rMBP and TB Display connected and working properly would be appreciated.

O, one more question. Do I have to purchase a seperate Applecare for the TB Display or will it be covered with the rMBP if I purchased them at the same time? what about the external superdrive?

Much Thanks.