Thanks for presenting such a civilised rant!

You've got a clear claim for the non-functioning IFE. Compensation comes in the form of miles.

You've got a clear claim for the costs you incurred along the way re meals (c/- EU Regs) and missing baggage. Compensation comes in the form of cash.

As to the rest of it there are arguments both ways. Technically you've not got a great case, but there seem to have been a few cock-up along the way which could arguably swing it for you.

I'd say write to BA attaching receipts (and pleasingly your post is well enough composed that you can pretty much cut and paste) and see what they say. You probably won;t get exactly what you want but your argument is well composed enough and easy to understand that you have a chance.