easy questions:
It says all we have to do is register and we get 50% bonus miles on select north American flights this fall.

1) what's the catch and why do we do even have to register?
2) I know the bonus is not status miles but will I still get status miles for the normal miles?
3) what if I'm flying to Austin from Vancouver via Calgary.. Would I get the bonus miles for the YVR tp Calgary portion?

Thanks ok advance to all who answer.