Muslim Non Muslim Marriage
Ghamidi Sb focus on understanding of principle. Once you understand the principle then you can easily decide what is correct or not. About your question that only Allah through Prophet Mohammad saw can tell about mushriks . My question to you is “Are Hindus/Mormonism/ Paganism” are monotheistic religion? Dont they have multiple gods? You can only be unsure about christians are they polytheist or monotheist. In this regard, in one of video posted in above links, Ghamidi sab has suggested that its better not to marry outside Islam (rephrased wordings).