Just as couple of questions regarding lifestyle at BA. First of all, are applications to change fleet decided by seniority and if so, does this make a fleet change after the minimum of 5 years on your starting type unlikely?
You're correct in that everything is seniority based. Anyone can bid for anything whether you're frozen or not. If you're senior enough, unfrozen (the company can and does waive freezes if it needs to) and there are vacancies, you'll get a slot on whichever fleet*. At the end of a five year engagement freeze, it would be rare not to be senior enough to move to longhaul from shorthaul.
*This doesn't strictly apply to command bids. You must have sufficient experience (ATPL, hours, etc) and then it entitles you to the course
not the command. You'll only get the command if you pass the course.
Secondly, it seems to be widely accepted that new First Officers work practically every weekend and have very little choice over their rosters, but I don't see how this can't be at least partly avoided. I think pilots get 4 weeks annual leave (?) Is there any minimum length of leave that can be taken at a time, or could you say use 10/15 days of leave to book off 5/6 weekends and a few special family occasions over the course of a year? If you did this and got lucky/bidded tactically you could surely get around 1 weekend a month off?
You get six weeks "leave" per year, three weeks per season (in fact, two of those weeks are called Duty Free Weeks and are slightly different in concept - although you are still guaranteed that week off). All leave blocks start on a Saturday. Leave is only released in one week or two week blocks but creative bidding can add more days on if needed. Also, when you do a reserve block, you get a number of fixed days off which always include a weekend.
In essence, you can guarantee six weekends a year from leave (plus a couple extra through tactical bidding if you play your cards right) and one weekend each time you do a reserve block.