Big Dog's:
I think you have summed things up about right. At the end of the day BALPA will go along with whoever is most likely to pay their salaries.
In my career so far, I have been involved with BALPA, ALPA, The International Brotherhood of Teamsters and God knows how many other "negotiating bodies".
At the end of the day, I decided that it was much more practical (at our level of aviation) to have an "In-House PLC". This has worked incredibly well. Not long ago we negotiated a bloody good deal which involved much animosity from the management but who finally came to realise that we both had the Company's interests at heart.
After all, the only benefit of being in BALPA is the so-called "legal benefits". The only trouble with that is that BALPA can choose not to represent you if they don't think they can win.
To this extent I got involved in the early days of Aircrew Legal Protection which, for around £120 per year guarantees to represent your ass (instant legal representation regardless of blame) if you happen slide off the end of the Athens runway.
I wish you well in GB Airways. I have fond memory of when GibAir first got going with a DC-3 (G-AMFV?). It went from Gib to Tangier several times a day.
One night, the RAF lads at North Front in "high spirits" got a pot of black paint and painted a "YO" in front of "Gibair"!
We thought this to be amusing but the crusty old ****** who had to fly it first thing in the morning was not amused!
Good Luck.
PS. I no longer have an interest in Aircrew Legal Protection Ltd except as a customer.