A few questions I would like to pose on resources....
Should an iron mine ever play out? The mine startw with a set amount of iron and can eventually be depleted. Maybe a minor spell could reveal the total amount available. I personally like the idea, but it isn't anything I would get to worked up about either way.
Should resources come in different qualities? Not just the total amount of resource that is there, but the amount of resource it can produce at a base level. Some mines might produce 5/turn with no upgrades to the mine, others might be able to do 10 or 15. Again, I like the idea of some diversity between same type resource nodes, but not something I would really freak about either way.
Should there be mixed resources? To mine Adamantium you would have to have the relevant research done, but might it be possible for your iron mine to also produce a small amount of adamantium per turn? or even crystals? Just throwing ideas out there. 
Any rare/unique resources like meteorite shards for making a one-of a kind sword? Should that type of thing jsut show up randomly at your regular mine, should they be found lying around on the ground, or should they be a random event? Or combinations of all these or other ideas?
Sorry, I was bored. Gonna go check survey monkey to see if more people have taken the survey. 