Scenario #1 will not happen. Our sun is too small to supernova. It will become a red giant as they describe, but it won't explode.
Most of these aren't what I'd call "overlooked," since they're trotted out whenever the subject comes up. A more interesting list would be the most likely causes of extinction, but coming up with likelihoods will be hard.
Yeah, that particle accelerator one (#2) is talked about every freakin' time they run one of those tests. And how many disaster films have we had about volcanos? Overlooked my ass
I saw this thing about how in today's age nothing can be 'underrated' or similarly 'overlooked' because everyone and their brother has a blog about how something is underrated/overlooked and then it is no longer underrated/overlooked by definition.
And I've seen most of these mentioned in common doomsdays top 10 lists.