Even if you had access to the full size simulator, without some serious training in how to warm up the beast, you would not get far in the actual control room.
Warming up too fast, will cause many reactors to level off from poisoning that can take days to recover from. Other issues like Wigner effect in the graphite of an RBMK could cause surprises. There are things like mechanical limits on how many rods you can pull at once, by design.
If you read the translation of one of the more candid Russian reports on Chernobyl, much of what would be known physics to a US operator was considered classified need to know by the Russians at the time, partially leading to the disaster. I do not have time to download the sim, but does it require you to pre-warm the coolant by running the pumps before startup? Do you have to insert a start-up source? Do you have to pull the low level reactivity monitor out of the core before throttling up? Not knowing little things like that can halt the sequence easily enough.
Pulling the hot reactor fuel without a storage cask or years of cool down in the fuel pool would have you dead in an hour or two, if not in 15 minutes.
You would not live long enough to fab even a dirty bomb working close up with even a few grams of hot spent fuel. There is a reason they have it cool down before transporting to a hot cell.
Pu production is highly specialized, enough that it is very easy to spot on a IAEA inspection.
Having the training software out there is good for education and understanding. No matter what side of the debate your on, having some experience at running a sim could make you more aware of the care, expense, and planning that is required to commission, run, or decommission a reactor. As my state (Ohio) is tied up with the House Bill Six reactor bailout fiasco right now, I can't see how having a bit of education on the issue is a bad thing.
This video makes it look easy, but note the Cherenkov glow. That fuel is really, really radioactive, requiring the facilities of a nation-state to handle. You think the cranes you'd need to move the fuel would not be a give away? Reactor crime would not be a one person effort either. You think the RO has access to the the keys to open the containment, and the fuel pool gates and channels?
https://youtu.be/DogPLc0IzQMNon-issue.
Steve