Bogey Ben,
You wrote a long post but actually said very little. In one respect this is good as you do not want to bare your soul in public before OASC etc.
You say
by the time my qualifications meet the initial criteria required before I’m eligible to be even considered, I’m going to be 23 years old (another 2 months and I’ll be 24).
and Sam Rutherford guessed that you are., or will be, a graduate.
If you will be a graduate then you should have achieved the initial criteria 6 years ago, namely 5 GSCE Grade C or above incl English and Maths, an 2 A-levels. In other words you could have applied then. If you are only just getting these qualifications then you would be a weak candidate in comparision with others of your age who are most likely graduates.
If you are a graduate then you have still left it too late as you need to be no older than 24 on your firt day at IOT. However if you are an exceptional graduand and have exceptional pilot apptitude skills and can write a good case then you might be considered.
Your first hurdle is to pursuade the AFCO that you should be considered.
Other than your late entry in the race, your post on pprune looks promising.