i am not EY, but to your last question i could reply:
because they dont find enough A330/340 rated guys, so they take some A320 folks and CCQized them...
it is way cheaper like that than pay for a full conversion course for a non-airbus rated guy...
oh yes i forgot:
abu dhabi is i think nice if you are single, night life is ok, bar and restaurant too. if you have kids that might end up as an expensive place to live. housing is quite expensive.
for family life i think bahrain is nice, and still not as expensive as doha, or dubai. Bahrain is maybe sometimes a little bit too "small"... Night life is ok, but most of the times you end up in the same places with other (or the same) expats...
Doha: been there only for training, so I HEARD that most of people dont like it too much, and housing is gone crazy the last months... It seems also that it is not the best place to go out...
Dubai is also ok for families, as far as you have there good schools, but dubai as most of you know is very expensive... Some guys based in Abu Dhabi live in Dubai, it is a good hour by road depending on where you live in dubai...
I hope it helps...