Italian term (edited): completare le clausole non valide / le lacune

close does work for the second instance and preferably not translatable as loopholes.

In English law, the 'blue pencil test' would mean that a court would strike down the nugatory provision of a severable contract and let th rest of the contract stand. That's not so with an 'inseverable' so non-splittable contract.

Execute legal definition of Execute
Search domain legal-dictionary.thefreedictionary.com/executehttps://legal-dictionary.thefreedictionary.com/execute
execute. v. 1) to finish, complete, or perform as required, as in fulfilling one's obligations under a contract or a court order. 2) to sign and otherwise complete a document, such as acknowledging the signature if required to make the document valid.
Sounds like a modified "severability clause". Basically it says that if any clause is inapplicable, the parties will undertake to execute the contract" in a manner fit to ensure the achievement of its goals. Severability legal definition of severability
Search domain legal-dictionary.thefreedictionary.com/severabilityhttps://legal-dictionary.thefreedictionary.com/severability
severability the rule of construction of contracts that allows a court to ignore a part of a contract that would render it in some way defective and to read instead what is left. It has been applied to restrictive covenants where, if the words are capable of being so read, the court will ignore a severe restriction and allow a lesser restriction.