it depends on experience really in actual plastering a lot more than they tell students , when i left college in 1987 with city and guilds the plasterer i went on with gave his labourer the job i went for and made me labourer for obvious reasons , If you can plasterer well and up to an ok speed and you find a small company you maybe fine but i would not rule our doing some plastering labouring to get in the door unless you already did that 10 years or something ! if your honest and the contractor needs a pair of hands and you offer to muck in it helps a lot early on.
As far as work goes i think you have to be prepared to travel , i am in Cornwall , its terrible for work down here it seems unless you really network a lot...i am looking to relocate as agencies seem to have taken over and they think shelf stacker wages are fine for hard labour
good luck , something always shows up in the end