you are right, you don't pick your base they do, would flying little work for you on a 5/3 base with no time to commute home? i.e. not a lot of money and no time at home and stuck in some shi**y base?
as for hours, 30-70 in winter months,,,,, 70-100 in summer months
any smaller base will = less flying in winter due having crewing for summer schedule and less flights/aircraft operating in winter.
bigger bases pull in floaters and temp based crews in summer to ramp up crewing numbers so will be a bit busier in the winter than the smaller bases as its down to the core crew.
summer 2012 is gonna be BUSY everywhere.