Thank you chaps, and particularly naturals - most illuminating. I have already resolved to return next year, and am dedicating 45 mins every day to learning about BA (and occasionally other topics such as jet engine technology), plus spending 3h+ per day on an OU BSc in Natural Sciences, which should cover off the maths/science elements.
I have also taken a new job based partially in Slough so that I am conveniently placed to visit Waterside, tour the Heritage Collection, become familiar with the Heathrow, Gatwick and London City operations, have a go on the 737 simulator etc. etc., as well as visiting my "local" Concorde at Manchester Airport whilst back home. I have seriously considered taking advantage of some of the cheap day fares just to get a feel for the BA "experience" and am looking for opportunities to get onboard a 787 (my preferred "target" aircraft).
I am also working on various more desirable personal traits (I have been described as abrasive
); in addition, I will be booking in for one of the OAA selection days to gain further experience of the process and see how I am progressing (though I appreciate their own criteria differ slightly). Finally, I'm planning on adding an Advanced PPL + Basic Aero rating (from Ultimate High) and another 50 hours to my licence this year, as despite having no issues with the technical assessment last time there is, as you say, always room for improvement, and I can't start CPL/ATPL exams without counting myself out of the FPP process.
Any other feedback gratefully taken on board, and perhaps this gives other hopefuls some ideas - will look good when I don't even get past stage 1, eh?