Quoth ExXB:
Not sure if these specific T&Cs have been tested in court but (IMHO) appear to be imbalanced (i.e. they have all the protection, the customer has little) and deny any possibility of appeal
I'd say that's a very important point and the reason why airlines shy away from pursuing 'costs' in courts, even the small claims court.
Airline contracts are adhesive and homogenous; that is, they all impose un-negotiable terms and they are all essentially identical between carriers. An airline can put whatever it likes in its T&Cs but a court has the ability to strike-out the term as being unreasonable given the manner in which the contract was imposed.
And 'he could have taken the train instead' isn't considered a defence against unreasonable terms.