A bit surprising that BMIBaby management would allow the attrition to occur with Easy, Ryanair, Jet2/Channex, Thomsonfly, BA and others hiring at the moment. Are all new employees required to pay a prorated training bond if they leave within a specified time? That may be the reason management is not so worried - they have you by the ball$...
You mention junky aircraft. Are we talking really aged 737-300s/500s? Are they at least EFIS equipped? I have seen 737-300s with just FMS and no EFIS.
Lastly, would would be the starting pay for newhire FOs - take home per month?
Cheers