Hey Rupert,
This is an interesting project – unfortunately is a custom coding project, which we can not help with 🙁
As one last quick note before closing this thread, you mention using a custom field to store the credit score – and so to address your question about how to “call the attended events out with the associated score”, it seems like using WP_Query and/or pre_get_posts to display events based on the value of that custom field should do the trick just fine.
Best of luck with your custom coding!
Cheers,
George