Honestly the only Zoro-Monet interaction that ever interested me was Zoro's air slash hurting her, since that proved that Haki could be imbued into air slashes. I think at this point that's been proven a few more times, but it was quite the point of debate back in the day.
I do disagree with you about Logias being just their element in human form, because it seems to suggest they have no genuinely human form left. I think, especially given how Haki affects them, their physical human form gets mapped in some sense to their element, so even if Enel turns himself into a giant electric monster, punching the monster's face still hurts Enel in the corresponding location of his own face. It's not that Enel lost his human form and it became all electricity, but that even as he turns into his element, it's always possible to find an arm or leg mapped in some way to however they've transformed.
I think there is a distinction within Logias between transformed element and just created element. Created elements have no connection to the original user, and harming them doesn't harm the user. However, transformed element is the elemental extension of the user which is susceptible to harm. Put a different way, it is the part of the user that has transformed into the element.
A good example of this is Vergo vs Smoker - when Vergo grabs his smoke-arms, he is grabbing a part of the element that maps to Smoker's real arm, which is why Smoker feels it and can be flipped over, rather than it just being smoke he created that couldn't be grabbed. Similarly, Monet's face when she was cut wasn't just a snow creation of her face that she controlled, but her real face was present there, and thus she was susceptible to damage. I don't think anyone would suggest that if Zoro started laying into the snow on the ground next to him that she created that she would be wounded, since that snow was created, and is not her human form transformed into snow.
The reason I belabour this is because I think that your definition sounds like there is no distinction between the created element and the transformed element, since everything is just "element" and the "human form" in your definition seems more like an arbitrary decision of the user to retain that form rather than the ultimate truth of that person. But, I would reject such a definition, because I think a distinction must be made between the element that can be hurt, vs the element that can't, and similarly why Logias appear to retain a fully human anatomy (e.g. they still bleed when wounded). Maybe there's an elaboration of your definition that can reconcile these things?