Straight away. They are always looking for experienced baristas.
no they train people
You would definitely be trained in McCafe straight away as that would be the easiest and quickest way for you to learn the systems
After initial training, you'll be able to be introduced to McCafe depending on the number of staff available to do it & your competency in the general role of presenting, serving etc.
Work your way up most likely
Absolutely not - they hate driven and independent workers.
Depends on the restaurant, they may need more McCafe workers and place you there often, but you will be trained in more general areas in either the front area or kitchen first. If you want to work in McCafe mention your previous barista training ASAP.
You could start in their possibly they tend to stick to their regular staff as they like to keep their coffee enthusiastics happy about their coffee that never changes to displease them too often. They are possibly the #1 category amoung the different food genders to be the most popular and pickiest to please.