Q 2: Is it permissible to participate with
Mushriks (those who associate others with Allah in His Divinity or worship)
in their daughters' marriage contracts?
A:
It is impermissible
for Muslims to take part with
Mushriks in writing their daughters' marriage contracts, as this entails loyalty to them and satisfaction with their Kufr (disbelief) and rejection of Islam, the religion other than which Allah (Exalted be He) does not accept. You can refer to the book written by Shaykh-ul-Islam
Ahmad ibn Taymiyyah (may Allah be merciful to him) entitled "Iqtida' Al-Sirat Al-Mustaqim". This issue and others like it have been explained in detail. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.