[Q]

One more thing:
The AI can handle plagues, if you give them a population transport design with a medical bay in it!
So I think you could use the plague intel project without being unfair against an AI empire. More important seems to me that the plague level is not too high, otherwise the entire population is dead before the ship with the medical bay arrives.
And I like the idea to link these projects to the tech levels of the corresponding weapons. So you still have to research quite a lot before you can use them and IMO these super intel projects should be expensive, very very expensive!