Plodding Along,
Nice summary, I think - and especially worth restating that BASSA's offer was temporary, to be repaid at the end of the business plan. (Whether it was £54m or £174m is moot, if the saving was temporary it didn't meet BA's criteria (no other department has refused to negotiate on permenant change.))
The only point I would make is that the initial £82m, and latterly £140m saving, is over the life of the BP. ie: 2 years.
It's not a £82m (£140m) year-on-year saving, more like £60m y-o-y once fleet contraction has been stripped out of the figures.
£60m is, what, 10% of the IFCE budget- ish?
So in your 3 options, the work harder/pay-cut balance would be more along the lines of 10%...
All IMHO and willing to be corrected!