Re: The Missing FUD!
Modelling a simple, two atom molecule, is not the same as making it, nor is it the same as modelling a three or four atom molecule, the effort involved in which scales exponentially, I believe*. I googled the structure of novichok (or the supposed structure, I guess it's actually not published). It has 24 atoms in it. Any integer above 1, raised to the power of 24 give a large number, that is the number of times more qubits such a computer is going to need to do the equivalent task. For example, if adding an atom only makes the job twice as hard (and it's likely to actually be more than that due tot eh rising degrees of freedom), then that number is 2^24, 16,777,216. Multiply that by your original 16 qubits, and this suggests you're going to need something in the order of 268 million to just model that molecule's structure. This does rely on a number of assumptions, but you get the general picture.
And then, it certainly is not the same as modelling its interactions with other molecules, and especially not those involved in biological systems, which tend to be proteins with a very large number of atoms in them (typically tens to hundreds of thousands, IIRC). You'd need to include all of those atoms in your model. What's 2^100,000? The Windows calculator says "Overflow".
Things like Novichok only have "remarkable" properties because of their interactions with specific vital metabolic processes. I believe the mechanism of action here is to bind to specific active sites of specific proteins to prevent them from interacting with their normal substrates, and thus preventing normal signalling for nerves, leading to paralysis and death. Good luck modelling that with any computer let alone a "quantum" one with less processing power than a Z80.
This doesn't mean that this won't be an issue some day in the future with developing new and nasty poisons via computer modelling, but I somehow suspect the current way of doing things (making analogues of known poisons in a lab and seeing how nasty they are by exposing lab animals to them) will still be more effective for those individuals who are unpleasant enough to want to do such things.
*I stand to be corrected, but my understanding is that in computational chemistry, effort does not scale linearly with complexity, largely because the number of degrees of freedom is an nPr kind of thing.