Most of this isn’t actually that crazy. It’s possible to discern atomic efforts by monitoring local wildlife. It’s not a sure thing but it is an avenue of surveillance.
It raises the question though of precisely why would they need to keep secret a program they’ve claimed to be fully open and honest about.
I am not sure they ever claimed or agreed to be "fully open and honest about" anything anything. Obama's deal did not really require anything of Iran that precluded them from keeping secrets. I think Iran is required to do their own inspections to make sure that Iran is compliant with Iran's deal. Then, I think they are supposed to report the findings to us.
Yes, it is all laughable, including the lizards. I think it would be in the best interest of all the world if Iran and NK were to have a series of Nuclear accidents (read: accidental detonations in launch silos).