4AD,
Sorry for the late reply, been away. Don't hold your breath about weekends off. You may be able to swap trips with colleagues if you're desperate but (certainly with Bidline at LHR) you're unlikely to see very many. As someone said, plan on zero and any more is a bonus. There may be more chance of the odd weekend off at LGW (they use the Carmen bidding system which I'm not familiar with).
Expect 15 years plus to a short haul command. I'm one of the luckier ones. As I joined at the start of the retirement bulge, I can expect a junior shorthaul command after around 12 years (basically another 5) and a junior longhaul command around 17 years (another 10). There are a large number of us who will be in the left seat for 20 years potentially so keep in mind that it's "Dead Man's Shoes". Depending on your age (ie. at what point you will retire), a long haul command may not ever happen for you.
It's not all doom and gloom by any means. Roster stability is like nothing else. Changes are pretty rare after publication. The money isn't bad either, although not as good as it used to be.
Keep in mind though, all LHR fleets are contracted for the full 900 flying hours per year (or 1043 credit hours in actual fact - the end result is pretty much the same
). If you want longhaul, this is worth taking into account when our nearest neighbours in red work to 750 flying hours for not dissimilar money.