You know the old story - a £100 overdraft is your problem, a million pound overdraft is the bank's problem. In this case for banks read aircraft leasing companies. The point of the parable is that it very unlikely that BA will do a Swissair.
There will be changes, some of them very traumatic for the individuals concerned, but BA will probably weather the current storm in a recognisable shape.
BA might well be overstaffed, but it is very difficult to make a valid comparison of employees per a/c. It depends on what services are bought in, and what are done in house. Route network and size of aircraft also affect the numbers.
In the short term exposure to N.Atlantic routes is probably the critical factor. BA is much less exposed than say Virgin.
All of us, whatever our place in the UK aviation sector need BA or its equivalent. VERY generally BA sets standards of salaries and conditions of service that many outside BA aspire to.
The point of this whole post - lets stop talking down BA or any other airline. Right now we need to be positive. There can be no winners - only losers. (OK the low cost airlines will probably do allright for the time being, but they are predominately in a niche liesure related price sensitive market and we need them too).
Remember the song from "The life of Brian!"