I wouldn't recommend that strategy, simply because it could greatly limit your troubleshooting capabilities if something were to go wrong on the staging server.  You _Could_ do many of those tasks via the database, but if a site is hard down, it could complicate things.

In addition to the cautions presented above, you may have issues associated with outbound e-mails originating from the site administrator (for registration e-mails, password reminders, and the like).  Under your scenario, this account would not exist and there would likely be subsequent problems.

You might be able to circumvent these (and other) issues, but I would strongly recommend spending the all the time you'd put into hacking together a solution instead into other areas that will actually make your installation more secure.

Brandon