Where did you read Iridium is found near ancient vulcanic eruptions? I'm wondering if it would make sense to let Mount Planet provide an Iridium resource.
I've read about it in various descriptions of the dinosaur extinctions. There were/are theories that volcanic eruptions were the main thing driving it, and they were described as a potential source of the iridium that was found at the boundary. (I also checked the wikipedia page, just to make sure I wasn't remembering this wrong, and it does describe volcanic iridium sources as well:
http://en.wikipedia.org/wiki/Iridium#Occurrence
Whether or not you make mount planet a source is up to you. (I wouldn't know any more than you would whether this is plausible or not.)
On oil: tectonics does throw a pretty serious wrench in the process, since on earth a lot of oil deposits are formed in areas that than get uplifted and converted to land areas, so it would be very strange for oil ot be found in the ocean, but not on land
On fungicide: The explanation you wrote above is one I'd included in the description, although it may not have been clear. Given that the planetmind does have a lot of ways to influence planetary ecology aside from fungus (such as the carbon recycling.), the description would probably need to include some explanation/guesses by centauri scientists, of a purpose fungicidal plants serve, or some description of why the plants aren't threatening enough to be completely eliminated.
As for the proofreading, I do make a check afterwards, but might have missed a lot this time around. I think the resources are the last bit of civilopedia that is also found in regular Civ 4, but since gameplay changes are occuring I'll be checking the descriptions again to keep them fitting the changes.