Not necessarily, because clauses can be ruled invalid if they go against the law.
From the Unfair Terms in Consumer Contracts
Regulations 1999, which implements the EC Directive 93/13/EEC on unfair terms in consumer contracts (the Unfair Contract Terms Directive):
Excessive rights for the supplier. Cancellation of a contract by the supplier
can leave the consumer facing inconvenience at least, if not costs or other
problems. Where that is so, a unilateral right for the supplier to cancel
without any liability to do more than return prepayments is likely to be
considered unfair (see Group 6(b), on terms which exclude even that
liability).
That's one layer of regulation, but the problem with airlines is that there's yet another higher layer of regulations agreed at an international level to specifically govern and regulate air travel. It wouldn't at all surprise me if there's an international treaty governing the terms and conditions airlines can impose that trumps even EC Directives.
Unlikely. EasyJet is a UK/Europe based airline, and they mainly travel within Europe. I think they have tried to ignore a few EU directives before and got stung by the European courts, esp around compensation.
I've travelled EasyJet a couple of time, it's a cheap low cost airline. Just don't expect any customer service whatsoever if something goes wrong, it's like talking to a bunch of incompetent monkeys.
From the Unfair Terms in Consumer Contracts Regulations 1999, which implements the EC Directive 93/13/EEC on unfair terms in consumer contracts (the Unfair Contract Terms Directive):