I seriously doubt this, since the script functionality is constrained by the native dll functions on which they are built, and so I dont believe, that such versatality is possible unless the whole game is a script, but it is not. Its really, really hard to believe what you are saying
So you call him a liar, even though WE'VE DONE THESE THINGS, and you haven't even tried. Very nice.
Lua is extraordinarily flexible, and people have already come up with some spectacular uses, including religions and such. And seriously, unit stacking is in the XML; you change one value, and POOF, stacked units.
Here's a few modest changes I've added, through Lua, in my own mod:
> Nuke interception, with the percentages dynamically changing based on how many civs you're at war with and how many have anti-nuke systems (i.e., your enemies pool their interception abilities against you, with a diminishing returns aspect and some caps)
> EDIT: Forgot to mention Terraforming. Plant jungles, plant forests, create or remove hills, create new resource deposits, change snow into tundra into plains or desert into grassland, that sort of thing.
> Non-nuke bombardment weapons that damage all enemy units adjacent to the target unit as well.
> "Critical hit" abilities for units to deal extra damage or to spontaneously heal themselves at the start of a combat.
> Barbarians healing, and being given random promotions as the game goes on to make them more dangerous.
> A unit that steals promotions from the units it fights
> Wonders that give you a chance of stealing techs from other civs, in three different ways
> Units that can move across both land and sea
> A "Rookie" promotion that goes away after a unit's first fight, giving him -25% to combat but double XP in that first fight.
> A psionic class of units that adjust their strength based on the strength of the unit they're fighting; when fighting a stronger unit they'll get up to 25% stronger, when fighting a weaker unit they'll get up to 25% weaker.
> An "Empath" specialist that gives +1 Happiness to its city, and whose Great Person can be used to create a custom Monolith improvement that gives +3 Happiness in addition to its normal yields.
> A Wonder that gives every OTHER civ a permanent -10 to their Happiness.
> Buildings that give temporary promotions to friendly units that start their turn in that city
> Buildings that give temporary promotions to enemy units that are in your territory
> A national wonder that gives you warnings when another civ gets close to completing a Wonder of their own.
> A building type that adds a random chance of triggering a 1-turn Golden Age, with the chance depending on how many of those buildings you have and how big your empire is as a whole.
> A project that makes every Great Improvement (Academy, Manufactory, etc.) generate Great Person points of the appropriate type.
> When you build a spaceship, instead of ending the game it gives you a few extra bonuses (free policy, free tech, golden age), and any other civ that finishes their own spaceship within a randomized window will get a lesser bonus. At the end of that window, barbarians swarm all over the world, spaceships no longer can be built, and a few other mod-specific events trigger; after that point, special barbarian bases will begin to randomly spawn inside players' territory and create units until destroyed, with the types of units spawning becoming more dangerous as time goes on.
> A new victory condition that starts a 20-turn timer, causes everyone to declare war on you, and shrinks your cities by 1 each turn until the timer ends, at which point you win if you're still alive and no one else has won some other way.
There's more, but this should give an idea of what can be done, and all of the above use a grand total of FIVE Lua events. (Start of turn, end of turn, start of combat, end of combat, on unit created.) Okay, I also use a sixth event, start of game, but not for any of the above. Most of the above aren't even that complicated, so with a little effort you can add all sorts of things. The only real limitation, as mentioned before, is that the AI can't easily be taught to use these new functions so most of them have to be done in "passive" ways where the AI has no decisions to make. The DLL will allow us to fix that, but even within the limits we have now there's a tremendous amount that can be done.
And there are HUNDREDS of other events out there...