The final selection board is run by BA at Cranebank, and if you pass that, there are no more selection interviews to go through. Of course, you still have to pass the course.
If there are suitable flying jobs available (i.e. short haul places), then FPP graduates would get those. However, at the moment BA has a surplus of pilots, due to the BMI merger. Flight operations cannot hire anyone into BA whilst there is a surplus of pilots. This includes FPP cadets. I've heard this surplus will run until the end of 2013. Barring a further world crisis, significant oil price rise, world calamity, 911-type event, then BA should hire again in 2014.
In the early 1990s, during Gulf War 1, no cadets were taken on in pilot positions for a while. Some were offered cabin crew (which at the time paid more than first year cadet take home pay), others went elsewhere to fly. When jobs became available, many of those cadets came back to fly for BA. The difference then was the cadet got the training for free.
There is simply no way of knowing that BA will be able to offer, as 24 months is a long time in aviation. However, compulsory retirements will start happening again in 2016.