Which stations does these trains depart and arrive in?

A. K7011/7012 (Depart from Harbin North/West/East/South? Arrive in Yabuli North/West/East/South?)
B. Z1/2 (Depart from Beijing North/West/East/South? Arrive in Harbin North/West/East/South?)
C. Z15/16 (Depart from Beijing North/West/East/South? Arrive in Harbin North/West/East/South?)

Another question, does the train Z15/16 only contain all luxury soft sleepers (800 yuan) or do they also have the normal soft sleeper (400 yuan)?

First I wanted to buy the tickets from this website, but I don't have PayPal. So if I want to buy the tickets when I arrive in Beijing:
1. Where can I buy the train tickets in Beijing?
2. Can I buy for all the train trips I will make at one go (Beijing-Harbin-Beijing and Harbin-YBL-Harbin)? That is a total of 4 train trips.
3. Can I buy a Harbin-YBL-Harbin ticket in Beijing?
4. How many days before my train journey can I buy the ticket?

Thank you very much! I love this website! Only 7 days left before my trip! Very excited to get cold!
Warmest Regards,
Josh