Prohibition of eating products that are offered to gods and idols

Q: I want to ask regarding prasad which Hindus etc. offer such as sweets, fruits etc. In the Quran I didn't know of any verse regarding prohibiting this. What I found is prohibition of eating their meat which is not halal. Can u tell me any evidence from Quran and Sunnah regarding prohibition of vegetarian products like sweets etc except meat or complete prohibition on all types?

Authenticity of the kitaab "Fayzaan-e-Rahmat"

Q: My query is with regards to the authenticity and reliability of a kitaab - it's content, author and publishers. The name of the kitaab is "Fayzaan-e-Rahmat - Abundance of Mercy - A collection of Du'as for different occasions" by Maulana Muhammad Abdullah Darkwasti and jointly published by Zam Zam Publishers and Madrasah Arabia Islamia.

All the duaas are prescribed from Qur'aan and Hadith. Some of the prescribed wazifahs include Surah Yaaseen and it's seven mubeens/Shaykh Husain Ahmad Madani's nafl salaat prescription/other wazifahs of qadriyyah silsilah among many others. Can I undoubtedly and with full yaqeen supplicate to Allah Ta'ala through the means of these prescribed wazifahs?

Husband touching the wife in haidh

Q: I am aware that when a woman is on her periods the area from her belly button to her knees must be covered. But if a woman on her periods is wearing only underwear and the man is wearing only underwear and they both rub their private parts on each other, does this break their nikah as the woman was not covered only her private part was?