Applying in person as couple Express

Me and my girlfriend plan to travel from outside London to apply in person.
With the Express would we get our visa and passport back the same day? or would we need to travel back to London 3 working days later? Is express only 1 day quicker?
Would we need 2 copies of hotel/flight information? As I booked for both of us its my name on the hotels.
Can we start the online application before the 30 days and travel to CVASC closer to the time for the appointment?

Many thanks