MR777
If you <<live about an hour fron LHR round the M25, so I will be commuting,>> you are closer than most BA crew to LHR, and are not "commuting". "Commuting" in BA speak means flying to and from work, not using a humble motor car
As said above, Day Trips are "popular", so as a junior BL type, don't worry about those... It will be tours covering the weekends. If you are lucky enough to get a Sat night at home it'll be between the Thurs-Sat and Sun-Tue tours...
PM if you are willing to reveal your identity, and want more info. I happen to "know someone" who runs one of the bid programs that will let you see what the rosters are like, and get an idea of bidline <G>