1. Is the marriage contract valid Islamically and legally, even though the guardian was not the father, but rather the mother, grandfather, and maternal uncle, due to the father's estrangement, with his implicit knowledge and consent? 2. Is the contract valid despite an error in the acknowledgment of receipt for the immediate dowry, and the deferred dowry being specified as 5 kilograms of 21-karat gold, even though 24-karat is the common standard? 3. What is the difference between an Islamic contract and a civil contract, and is a contract in the Sharia court sufficient, or is another Islamic contract necessary?

The guardian (wali) is a condition for the validity of the marriage. The maternal grandfather (mother's father) and the maternal uncle are not among the guardians in marriage. There is no guardianship for relatives other than the 'asabat (agnatic relatives).

Therefore, your marriage arranged by your maternal grandfather or your maternal uncle is not valid. Your father's consent to your marriage is not sufficient; rather, it is a condition that your father himself marries you off or delegates someone else to do so.

However, if you got married based on the opinion of those who do not stipulate the guardian as a condition for the validity of the marriage, and the Sharia judge ruled the contract to be valid, then the contract is sound and cannot be annulled.

As for writing the prompt and deferred dowry in the contract and the disagreement concerning it, this has no effect on the validity of the contract. Marriage is valid even if no dowry is mentioned in the contract.