From my working experience as an employee and not in terms of management. Someone with less tallied working years could unsurp you if h/she is employed higher up in the heirachy; or, for some reason has a greater personal click with the heirachy. It's not right but unfortunately it can be like that. Maybe you can make a horizontal move in your workplace rather than think of how you are stuck in the enforced heirachial system?
This really depends on the workplace. If you are at a unionized workplace, they give preference to people based on how long the person has been there - seniority. However, non-unionized workplaces don't and tend to go on merit, not age.
Thank you, it's because my co'worker and I asked to get a week off this coming holidays but we were told that someone else had asked for 2 weeks off and that, that person had more right than us because he has more then 20yrs working here.