As you point out, Samus has blown up multiple planets as a part of her job. Link, canonically, lost to the bad guy once and had to have Hyrule pulled out of the fire by an eclectic bunch which included a child, a agoraphobic geezer, and a fish.
As an aside, where'd you get all that gravity stuff from? I've never heard anything like it. It doesn't make much sense either, to be honest.