You can get English maps at any information center or on the Internet.
People in big cities don't speak it well, but well enough to understand clearly, slowly spoken language. They don't expect foreigners to know any Japanese anyway. Public transportation in big cities have English on signs and ticket machines.
If you plan to use hotels for only 2 nights, yes, US$900 is plenty for those and for general entertainment expenses for a week. Figure 5000 yen for a business hotel (including breakfast).