Let me reply to you the question one by one la.
(1), (2) when you arrive to Japan, you could buy the Suica & NEC package. For a easy way, print it out the, and then shown to the any counter inside the airport, then the staff will show you how to go to the ticket office. You could buy the package there. last time i remeber i take the time was around 14:13 pm. arruve to Shinjuku around 15:30pm......
(3) The ticket office to the platform is very close, only 3-5 minutes will arrive. Again, the staff in there will shown to you how to go.
(4) Yes, it is JR station. and if you go to Shinjuku Prince. it is West Exit.
(5) when you returned, you better to take around 15:40pm schedule, as 16:28 was a little bit tigh. And you better bought the ticket one day before on the JR station. it will be safety.Moreover, The Narita Express ticket could bought in JR station ticket office. also depart from Shinjuku. and if you take North west airline to HK, it is to Narita terminal 2.
If you still have question, email me and i reply to you la.,..as i just return from Japan by Sep time.
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