First off I keep seeing a few scenarios about how Kirby can inhale large and/or heavy characters. Kirby’s copy ability does have its weight limits, evidenced in the show and games, even in forgotten land. Now he can somewhat inhale trucks so it maybe has something else to do with living characters. Maybe their self-awareness? Waddle-Dee’s are pretty mindless after all, but looking at some mini boss fights he can’t inhale them right away either and there isn’t a lot going on up there. It could be a combo of both, or their ability to resist? They are actually set out to fight Kirby, same with Scarfies, but not bronto Burt, King Dedede, or meta knight. So the limits, until proven otherwise, is the object/person’s ability to resist Kirby’s copy ability.

I do also think that Kirby is canonically the killer of one god, void termina. The other enemies are either demons or eldritch beings, or just flat out abominations created through wishing (looking at you, Marx) or science. Even Galactic knight could be considered an eldritch being, and even Kirby’s own species could be considered the same. Either way though, he does possess the power to really kill gods, but he’s only ever killed one god.

Those are the two biggest things I see people forgetting, but I could be forgetting something as well. Either way I know it’s all fake with suspension of belief but even with that every series has its rules and Kirby is no different.