Hi there,
with regards to early starts, GB sticks to the limit of Fatigue Avoidance (CAP371) of no more than 3 early starts in a row. To be honest though, they see this more as a target than a limit
This is mostly due to a lack of cabin crew. For this summer schedule, over 20 flights are still not crewed, so the current crew are being used on most of their stand bys.
Basically, GB crew is very friendly, and you'll almost always have a very nice day out. Cabin Services team is really bad though, their management skills are almost inexistant. Bottomline is that the treatment you receive is not the one you'd expect ...
Paywise... well, with one or two night stops, you clear approx £1,200 max.
IMHO, GB is great for gaining experience, but wouldn't consider it as a lifetime career.
If you do join, you'll have a great time with the crew, but do be aware of the FTL and CAP371 rules, as these are often bent in order to be able to crew all the flights.
Hope this info helped.