I learnt to read any write by mailing my wife/friends and watching TV a lot. Once you get going it isn't hard.
As, for jobs, you'd have to get a qualification in what is needed ,when an earthquake hits. Without one I doubt you'd have a chance. A lot of people from the States, especially the W.coast come to Japan to study earthquake architecture and structural support.
Hotels? I work in one (there at the moment). The best I could get you would be about 150 to 200 quid per night... Hostels are cheap but they sound a bit dodgy to be honest. If you stay out side Tokyo, in Saitama or Chiba, places can be a lot cheaper.
Trains are expensive here, whenever I go to Western Japan or somewhere in the North, I always go by plane. It's cheaper.
Never been on one myself but you can also get an overnight bus from Tokyo to Kyoto or Osaka which is cheap, about Y4000-ish.
Himeji... to be honest I'm not into all the "Japan" stuff, especially traditional things. In my opinion, if you've seen one casle, you've seen them all. Same thing with temples, every single one looks almost identical. Maybe I'm just uncultured.