A couple of points:
Assesment fee is Euro800, thats about £500.
AirAsia still haven't confirmed their choice for fleet renewnal. As a seasoned 737 operator it will take something huge for them to goto Airbus. Inital contract is for 2000hours. 737s will be with them for at least the next three years.
Ages on my course where 22, 25, 34 and 35. Others I know who also wwent thru ranged from 20 to 30 so age doesn't seem to matter on selection. One selection did select 6 but 3-4 is the norm.