This all looks like a case for the "reasonable man" of common law fame
The man on the Clapham omnibus would undoubtedly consider the private flight perfectly reasonable, even if you could argue about valuable consideration. He would also, I believe, consider that the flying school owner gave a free ride to the celebrity in the expectation of free publicity as he would not reasonably be expected to offer free transport to a member of the general public. That case does appear less clear-cut, however, although with the English legal system being what it is pleading guilty to avoid losing in court is sadly understandable.
Rather than argue about what valuable consideration does and doesn't mean (which is fun if you would like to be a lawyer, probably fairly irritating if you actually are a lawyer, and terribly dull for everybody else), isn't it better to just keep to reasonable behaviour without trying to push it? You may be able to argue that other behaviour is allowed, and a judge may even agree, but isn't it better to stick to what is clearly allowed, rather than arguing about what the ANO might mean? The same could be said for this endless IMC minima debate...