No: T&C cannot override the law, that is a national/EU law is still superior to anything that is written in the T&C. If there is a contrast between T&C and the law of course that T&C are just scratch paper.

Definitely not. you cant have T&C that are against the law, event if consumer has agreed to that. Like you cant sell your kidney even if you want to. Its illegal.

> T&C treated like "local" laws. so even if T&C does not make sense, usually courts are in favour of enforcing them. unless some severe contradiction with constitution or alike

It's not a "law", it's always under the law like any contract. And a court will not enforce illegal terms unless something very shady is afoot. The law always takes precedence, Even "lowly" laws, not just the constitution. In case of conflict the law wins so you can't have illegal provisions in the T&C even if you agree to them. They can give you extra rights but they can't take away the ones you have legally.

The principle is simple, the company isn't allowed to ask for illegal things. Your agreement is irrelevant because you are not entitled to legitimize an illegal demand.

The problem is you need to go to court if the company won't cooperate.