Thanks for the very comprehensive report HIDDY.
As BA crew, nothing you wrote about the BA First experience came as a surprise ... most of us agree that the hard product is well past its expiry date, and the soft product, including food, is subject to unacceptable degrees of variation - as became apparent to you during your experience.
The pre-departure nuts will be gone, as will the canapes and chocolates in the next couple of days (cost-cutting). Nuts will be offered after take-off, and the canapes are to be replaced with amuse-bouches.
As for the crew cutting corners - there really is no excuse - but it's BA after all .... still a lottery, especially in the Economy cabins. Changes are under way, but it will take time.