I have found the roster stability to be generally pretty good. Home most nights. Rarely get roster changes unless some major problems, like Spaniards on strike or 3 aircraft tech in one day, but that rarely happens!
Average 500-600 hours per year flying. If you do more than 800 hours a year they pay extortionate overtime rates so will generally choose to stop you flying rather than pay. So you can pretty much guarantee you won't do more than 800 hours a year. Sectors are generally 2-5 hours on short haul, usually fly an out and back.
I understand your concerns, and although there will be events you miss, there are ways round it, certainly in Air 2000.
There are basings all over the country, where are you looking for? Generally they are pretty good at getting you into the base you want and keeping you there.
Standbys are, as previously mentioned, 8 hours long with a one and a half hour call out. Depends on base, but generally called out maybe up to 5 times per year. All standbys are home standbys, and as long as you are contactable (eg. mobile phone) and are within an hour and a half of the airport you're OK.
We have a system whereby you get 12 Requested Days Off (RDOs) per season. That is 12 in summer, 12 in winter. If you want a weekend day you have to use 2 RDOs, ie. you cannot only book at Saturday you have to book the Sat and Sun. There is a limit of 3 RDOs per month and a limit on weekends, I think its 6 weekend days per season. But you get rostered days off at weekends sometimes too. You also get Personal Days (PDOs) which can be wife's birthday and anniversary and they will try and keep them free for you, but for a guarantee you are better using the RDOs.
As for leave, there is a rotating seniority system. So you take it in turns to get first pick. You cannot bid for the same weeks two years in a row. You can bid for either Xmas or New Year leave and you only work one or the other. You can also volunteer to work one or the other thereby getting the other one off. Once you know people in the company you can sometimes arrange swaps too.