I like the shuttle, because we actually see a rusty shuttle in the first shot when Rey is inside the ruins of the Death Star. So Ben could‘be presumably taken that one.
The visual of panning down (or up, like Hal suggested) to the red nebula is cool, and with some quiet, spooky music, it could perhaps make the film start a little slower and more mysterious. I personally like the idea of the film not having a bombastic opening, but something darker and quieter.
But I do agree with Hal that his edits typically don’t stray too radically from the source material. If you keep the Mustafar opening, I honestly think the establishing shot poppa made with the TIEs flying over the forest would be enough to help smooth out the transition from space to the planet surface. Any other shots would be too much. It’s cool to see all of these options, but one shot is enough.
If people wanted to see Vader’s castle, maybe we could use it as an establishing shot for when Kylo rebuilds his helmet. I wouldn’t use it at the beginning of the film though.
I might have a go at some of those vfx ideas that haven’t been played with it. There’s still so much beyond the opening that I think needs to be touched on, too.