Also, even if the claim about the Casimir Effect is correct, since the Casimir Effect occurs between a pair of uncharged plates, the "warp bubble" would have to be between the plates--but that means the warp bubble can't move the plates, so using it as a "warp drive" would not be possible.

That said I think you still need such huge energies that it's impractical.

The geometries in question don't generate negative energy, they are generated by negative energy (which actually isn't a very good term for the kind of stress-energy that is involved). This paper is just talking about different possible geometries that could exist between Casimir plates, based on different possible configurations of "vacuum energy" that could exist between the plates. Even if one of these geometries turned out to be a "warp bubble", it still wouldn't change the issue that I described before, that all of this is taking place between uncharged plates, and the plates are outside the "warp bubble" so the bubble can't move them, so this is not a viable option for an actual "warp drive".