But at no point does Baelfire take the dagger and order his father to stop or anything with the dagger.
Yes, this. If they actually wanted to retcon the dagger into the One Ring, then fine — but they’d need to do a lot more work to make it plausible. Along the same lines, if the dagger is such a corrupting influence (presumably once’s you’ve held it and ordered a Dark One around with it), then how come Gideon just hands it back, no questions asked? Wouldn’t the logical reaction be “ooh, I got me a Dark One, lets go take out the Black Fairy now”? And why would Rumple give it out to Bae in the first place if it has such a horrible effect (unless, of course, he doesn’t know)?
They do have material to work with, both in-universe and in terms of folkloric tropes if they wanted to suggest that this sort of power is both literally and figuratively corrupting. It certainly would explain why no one tried to order the Dark One out of commission, and locked the dagger away — which, of course, has a lot of precedents in all sorts of fairy tales. They could have done such an interesting speculation on why the proverbial genie always ends up imprisoned in some lamp somewhere: that eventually someone somewhere grows a brain and realizes that this kind of power is bad news for everyone.
But my point is that if we all have to collectively do this much work to make this whole thing make any sense at all, they’re doing it wrong.