Planning a trip in Xian

Hi,

I am trying to plan a single day trip in the city. I am trying to visit: the Terracotta Warriors, the city wall (only a portion, not the whole thing), and the Big Wild Goose Pagoda.

I have a few questions just to clarify my trip.

1) Can I buy a round-trip ticket (to terracotta and back) at the XA railway station so I don't have to buy the ticket twice?

2) Since I am trying to cram everything into 1 day, which portion of the city wall should I focus on to see the best views? The page on this website about the city wall has a bit too much information so I'm not sure exactly what to do. I am looking to spend at most 2 hours at the wall. Should I consider taking one of those sightseeing buses or simply climb up?

3) What is the most convenient way from the city wall to the Big Wild Goose Pagoda (I'm looking for several options)? I would also like to know how much a taxi trip would cost from the southern portion of the wall to the Pagoda.

Thanks!