I wouldn't get a rail pass if you are just going to be traveling between Hachioji and Tokyo proper, it'd be a waste of money. The train only costs about 300-400 yen each way, but it's a pretty long ride. The rail pass is only worth getting if you plan on doing extensive travel throughout the country, or taking the shinkansen more than once.
Hachioji is an outer suburb of Tokyo. It's got a lively area surrounding the station, but my friend from there considers it inaka (boonies), and says there's not much there. From my experience it's a nice place but a far cry from the bustle of Tokyo proper.
I couldn't tell you about the phone, I've heard so many different things I don't know what to believe anymore. I recommend taking a Japanese friend to an electronics store that deals in a variety of services and having them look into it for you, if you can't get anyone to do the research for you online.
I never stayed in Hachioji, so I'm unsure of housing availability.