Sure, but how? No matter how hard I punch a cloud, it's not leaving the atmosphere. Also I'm pretty sure DBZ has had anyone who touches the sun be destroyed.
I discount filler because it gets discounted by, well everything else in DBZ. By everything else I'm talking about the manga, DBZ Kai, stuff like that. And again, I'm not talking about Superman, though I'd say it's harder to do with Superman because the comics are an absolute mess. The is no order at all to what they are doing.
Hey if you want to discount that guys calculations, that's your prerogative. Just like it's mine to believe him over you.
As for me, well I discount 100% of the information out of those extra things and interviews and the like. Because as Reddish Mage already pointed out, Power levels are clearly BS. The exact number, all the calculations and crap? It's pointless. It has no impact on the story. I'd argue it has a negative impact on the story. And as far as I'm aware, the whole concept of power levels lasted for like two arcs. The Sayains, and the Freeza arc. Before that it was never mentioned. After that it was never mentioned (I think and not counting Movies).
And yeah, I prefer logic and common sense over character boasting. If someone can destroy the sun, then show me that. If they can't, and there is no evidence to suggest that they can. Then I'm going to consider it boasting.