Is it permissible to omit the shaddah and madd in "Ar-Rahman Ar-Rahim" and to omit the madd in "Ihdina" in Al-Fatiha?

Al-Fatiha is, by consensus, a part of the Quran, and whoever denies any part of it commits an act of disbelief (kufr). It is not permissible to distort Al-Fatiha by dropping shaddas (gemination marks) or letters, such as dropping the shadda and the alif from "Ar-Rahman" or the shadda and the yaa from "Ar-Rahim," or the alif from "Ihdina" when pausing. All the letters and shaddas of Al-Fatiha must be preserved. Whoever does not master it, their prayer is invalid unless they are a follower (ma'mum). Whoever denies a letter from the Quran that is agreed upon, or adds a letter that no one has recited, while knowing this, is a disbeliever.