To your first question: I think it’s pretty clearly the case that religion, specifically Christianity and Anglicanism, have been central to British culture and heritage for a very long time. It’s only very recently that Christianity has lost its place at the heart of British culture. (I’d like to read Bijan Omrani’s book on this topic.)
To your second: I’m one of a few people who’ve banged on about Anglofuturism, so I won’t speak for all of them. Speaking for myself, though, I’m not religious, and I have no sense that being religious is a requirement for Anglofuturism. (My podcast co-host Calum is a God-fearing man and might disagree.) Naturally, Anglofuturist depictions of the future invoke the country’s heritage, including its religious heritage, but I don’t think you have to be religious to enjoy the idea of a Bishopric of Mars.
Let me jump straight to the more interesting conceptual question! I think that EA, for all its interest in the future, is not very good at envisaging futures people actually want to live in, or might feel at home in. I think Anglofuturism does a much better job of that. I think the more tasteful versions of Anglofuturism draw on Lindy-er aesthetics than does EA, and are more responsive to the natural human inclination towards kinship.
This might, to an EA, be what Anglofuturism gets wrong. It depends on your moral calibration. If you are truly impartial then you would probably be unimpressed by a worldview that is informed by kinship. An EA could also accuse Anglofuturism of being overly whimsical in a world that’s on fire.
I’ll sign off here with sincere thanks to everyone who’s participated in this AMA.