...also, all baby flight crew are already type-rated on both 737-300/400/500 and on 737NGs - even though the airline doesn't have any yet.
It would therefore prove easier (and faster) to introduce NGs in baby's fleet (once they have enough ex-easyjet 737-300s

)
OK, so going A319/320

would probably make sense from an overall fleet/maintenance etc. point of view, and Airbus might even throw in a few type ratings for free as an incentive, but staying with Boeings would ensure a more seamless transition.
Doors to Automatic - bmi baby has its own AOC, so even if the bmi group went under, they would probably survive on their own. They do use the resources of bmi ops/crewing, but even that is due to change. Also, bmi still controls a massive 14% of slots at LHR; selling some of them would be one way to raise cash if needed. Can't see them going under anytime soon (even though I agree mainline isn't doing well and is trying hard to position itself between BA and the LCCs and decide how to best use the A330s; the extra summer charters ex BHX show that bmi has quite a bit of A320/321 spare capacity at week-ends ).
Cheers