Even if she weren't opaque, she'd still be extra-yummy-smelling and still have caused upheaval in Edward's life. Whether her opacity is really the reason she didn't get turned into a tasty snack is a question I've chosen not to address. I think the opacity exacerbated, but was not necessary for, Edward finding her romantically compelling.
Given Bella's inquisitive nature it seems likely that she would have found a way to immortality even without being super-vamp-bait.
It may also have been interesting if Luminosity was written from the perspective of a different character altogether. Perhaps Amanda. Not having been spoon fed immortal connections from day one while still being likely exposed to the risks of vampire attacks would be something of a challenge. Then she could develop her own more custom made vampire talent rather than inheriting Bella's (rather boring) one.
In the vein of the Harry Potter and the Methods of Rationality discussion threads this is the place to discuss anything relating to Alicorn's Twilight fanfic Luminosity. The fanfic is also archived on Alicorn's own website <strike>(warning: white text on black background)</strike>.
Previous discussion is hidden so deeply within the first Methods of Rationality thread that it's difficult to find even if you already know it exists.
Similar to how Eliezer's fanfic popularizes material from his sequences Alicorn is using the insights from her Luminosity sequence.
Spoilers for the fanfic itself as well as the original novels need and should not be hidden, but spoiler protection still applies for any other works of fiction, except for Harry Potter and the Methods of Rationality chapters more than a week old so we can freely discuss similarities and differences.
EDIT: Post-ginormous-spoiler discussion should go to the second thread. (If you have any doubt on whether you have reached the spoiler in question you have not.)