It should work okay on real-earth maps. The only downside of such a map is it gives us an advantage, since we know the layout of the terrain while the AI does not. Some maps I'd recommend trying are the PerfectWorld script included in the package, or continents-plus / pangaea-plus from the Explorers DLC.
I like most of these changes... however, why do the Nuclear Submarine and Missile Cruiser require Oil resources instead of
Aluminum?
If Uranium wasn't so scarce, I'd say that it should be required for the Nuclear Sub; but Aluminum makes more sense than Oil.
I suppose the Missile Cruiser could be Oil or Aluminum, so it's a toss up.
Slightly off-topic, but it seems like most ships should require more than one type of resource to produce. Oil makes sense as a required resource for a Battleship, but why not Iron? I know that Battleships are made from Steel, but the only difference between Iron and Steel is 0.2-2% carbon -- Steel is mostly comprised of Iron. I understand that Iron and Steel are plentiful in modern times, so that's probably why they're not required to produce units.
I suppose my point is that for over half the game, Iron (and Horses) are vital strategic resources -- Players often fight wars for them. I understand why Horses become obsolete strategic resources. However, Iron shouldn't become obsolete and unnecessary, because virtually every military unit from the Industrial to the Future era uses Iron.
If I were to create my own mod, ships would require the following resources:
Frigate = nothing
Ship of the Line = Iron
Ironclad = Iron, Coal
Destroyer = Iron
Battleship = 2 Iron, 1 Oil
Carrier = Iron
Submarine = Iron
Nuclear Submarine = Iron, Uranium
Missile Cruiser = 2 Iron
I'd also modify how Iron was distributed over time, so that in the Industrial era, all Iron deposits provide +50-100% as much Iron; the Modern era +100-200%; in the Future era Iron would remain the same, but Aluminum and Uranium would increase by +100% (but perhaps Oil would drop -50%).