I 'm sorry, I can't type Chinese right now......
Yes, your harddrive is WD-Green
1: Always USB first, after remove from PC just make sure no data is accessing
(You can tell by the sounds or wait for 1 mins)
2: I got the same one as you, but you better not open it, because it is completely different than normal harddrives, unless you know what is it inside, and what you gonna do.
3: Because high sound wave can damage the harddrive
4: Well, more usage = less living time, I always copy all the files to my OS harddrive and watch.