I'm a practicing Mormon, and I'm one by conversion as opposed to being born into it, so you don't need to tell me the distinctions between it and Orthodoxy/Catholicism. I'm not of the view that anybody is going to hell for having wacky cosmology, including those truly batshit cosmologies from the Nag Hammandi libraries or whatever.
Personal conduct, in the context one is placed in, is much more meaningful in the current Mormon view, than membership in any religion or church. We aren't supposed to know for certain how things up there truly are. It's supposed to be a mystery. So we can speculate, and some of those good guesses about what's going on up there might lead to good choices down here, that's not truly what we're going to be judged on.