The usage number indicates that the phone has been awake a lot longer than your usage notes would indicate, which to me indicates an issue with background operations, specifically push connections and/or other things that get refreshed in the background like subscribed calendars.

For an experiment, try turning off notifications and ALL push accounts (inc mobile me), all timed pull accounts, and temporarily disable any shared calendars. Then power the phone down and back up again just to be sure there's no cruft left.

Leaving BT and WiFi on do not significantly impact standby life at all (BT is parked, wifi is totally quiesced when in standby). GPS is only ever powered up in location apps so no need to alter location services.

This should result in very good standby life - though a less useful phone. Try it for a day and see what happens. I can say that it's unlikely to be a HW issue and I guess the 2.0/2.1/2.2 comments probably apply - ie 2.0 had awful battery life and later versions fixed several important bugs...

UK apple service should be great if you want to swap it, but I'm really not sure swapping then restoring your current setup onto a new phone is actually going to help you much.