It's still only two chances - hidden away on this page: "You can only apply for this position twice, so if your first application is unsuccessful, you can only apply one more time. Once your application is submitted it will be counted as one attempt."
Trainee air traffic controllers | Airservices
Shifts are typically 8 hours with some longer, some shorter. Console time depends on how busy it - when quiet it might be 60 on 30 off, when really busy it might be 150 on 30 off, but 90 on 30 off would be typical. Night shifts are a different kettle of fish and some towers are single man at least part of the time so you're it until your relief arrives.