Digitalarkivet Emigranter fra Trondheim Questions

I have a few questions about understanding the information on the Digitalarkivet Emigranter fra Trondheim record. There are two dates, "Date of reg." and "Date." The first I'm guessing is Date of registration. Is that when they had the contract made up with the shipping line? What's the second date for? Next question, this record shows my ancestors' final destination as Fergus Falls. Does this mean their ticket for steamship and railway to Fergus Falls, MN was paid for at the time of signing the contract? Would they have had to pay for a railway ticket when they were in Castle Garden? In 1884, was it more likely they would have sailed out of Trondheim to Christiania or have taken the train through Østerdalen Valley to Christiania? In case, you need to see the record, it's on page 235, Erik Peders of the Digitalarkivet. Thanks for any help you can give me.