I don't think so too much to get the job in Canada.
Yes, you must apply to a position and compete through exams, interviews and role play. This may be very difficult. The same goes for promotions.You must compete.You may be doing the same job for a very long time if you do not succeed the competitions.
Answered - Citizen Services Officer (Current Employee) - Montréal, QC
Yes. Government jobs tend to be competitively sought after.
Answered - Policy Analyst - Contract (Former Employee) - Ottawa, ON