Hi Aviator3200. I am not on the recruitment team, but my understanding is that all applications will be looked at and 'graded' to assess suitability. When you put in your application is irrelevant as long as it is submitted by the deadline. We obviously cannot interview everyone, so the most 'suitable' will get the call and some will inevitably be unsuccessful.
I am not sure I fully understand your question, but clearly being called for an interview does not guarantee a job. The selection process will be fair, but will require you to also pass a simulator session. Like all such processes, you cannot be sure when a job vacancy will appear even if you pass it - some people will get offers earlier than others as we can only train a certain number of people at any one time. Clearly it is not desirable to be sat around a hold pool for a long time waiting, but like the BA hold pool there is no absolute guarantee a job will come out of it until you have the offer in your hand. I hope that makes sense.