Regarding captains in training, 411 says:
Some airlines would have a hard time believing that short statement.
It's strictly supply versus demand, always has been, and unlikely to change anytime soon.
Not entirely true for cariers in India and China and some ME Carriers. Ab initio entrants are cultivated from day one into the airlines' culture up to their upgrade and sometimes beyond the line Captain.
F/Os at carriers ala FR or EZ may be a different story where the pay for their training, sit in the rigt seat until it's there time to upgrade and away they go after a year or two after their command upgrade to bigger and better. I don't know the philosophy of FR or EZ if the provide subtle hints or training while in the right seat to prepare their first officers for the left seat. Perhaps those pilots could shed light on the subject.