Because it is one of the key bludgeons of government tyranny. It’s not the handful of same sex weddings that will take place, but the exclusion in piecemeal of Christianity from the public square, the erosion of the family, and the thousand new laws that all conspire to overthrow the Judeo-Christian civilization and replace it with.... whatever they deem is new and progressive. But, in a word, tyranny.
Yes to #4. Think of the adoption of children by homosexuals, and the normalization of homosexuality in schoool textbooks.
Homosexual “marriage” has little to do with homosexual “marriage.”