Ok, I don't have BA's proposals about the hourly rate and when it would apply, so I have no reason to argue with your figure, but I am aware that the maximum duty per annum is 2000hrs of which 900hrs are flight time. So working on 2000hrs that still amounts to a variable pay of £5000.
And there we have a demonstration of BASSAs techniques. Tell the crew they wont like something, whip them into a frenzy but never tell them what they wont like.
The hourly rate is from check in to check out at LHR/LGW, whether you are on duty, flying, in a bar or asleep in a hotel room.
There is a qualification requirement for a pilot. A CPL/ATPL