BALHR your love for British Airways is as I have said before admirable. But you do not seem to grasp other peoples point of view.
It is very apparent to everyone the advantages in your proposition to BA however it is also apparent to everyone (with the probable exception of yourself) it has little or no advantage to Aer Lingus, so therefore what you propose is very unlikely to happen.
You also assume that FR would allow EI to buy back their shareholding, what basis do you have for believing this would be the case?
I only (so called) "Love" for the sole reason that its the main carrier of the UK (state/flag/national carrier is not relevent anymore) despite what VS seems to think, this means that BA's fate plays a large part on the running of the UK economy (jobs, connections etc)
The main advantages to all this are to BA, hence why I suggesting that in return BA deals with the "FR porblem" meaning that EI benefits from the fact they don't have to deal with a "difficult shareholder"
Also FR would sell their shareholding for the right price, which might be after BA's buys a big enough shareholding to block a takeover from them...