Marti, average take home on EF is roughly £1500/1600 - that's for a full month's work. BA Boi has answered your questions pretty damn well, take his advice & mine and just join up....
1stclass, your chances of not getting any nightstops at all are 99% provided you don't request them; the majority of crew DO want nightstops so there&backs as we call them are 10 a penny...you might get the odd split duty, but chances are you'll be able to get rid of it if you request a swap.