^ Well, they are very legible. But I think you need a slightly different approach if you'd want to balance this in a reasonable amount of time.
There are some minor mistakes (I could be wrong of course) such as line 183:
bForeignCore would always be True since you looped through all the civs
Good catch, I've corrected this.
But by far the most important issue with balancing Stability in general is the problem of parameter fitting.
Different factors of Stability are multiplied with different parameters and then summed with each other. These parameters, unless very carefully designed (a task which is not always possible), would always mean that some factors are grossly overweighted and would overwhelm the other factors.
For example, lines 192 - 219:
I think you have given iModifier too much weight by giving them too many possible components. This means no civ can expand much beyond their core territory because the punishment is too severe. Moreover, I don't think iModifier should be multiplicative at all. I think most of their components should be additive (i.e. they should be added to or subtracted from the population of each city, instead of being multiplied with it).
I think the way around this problem (of parameter fitting) is to make the Stability calculation robust. i.e. largely independent of the specific values of the parameters. One way to achieve this is through percentage calculations, which you have used in your economic section.
We could talk more on Google Talk if you wish.
Expansion stability ultimately relies on a percentage calculation. A penalty starts to kick in once your periphery score exceeds your core score (both of which are heavily based on population, weighted by a modifier, as you know), or in other words, makes up more than 50% of their combined score.
I don't see how weighting parameters could be completely avoided. Individual cities have to contribute more instability than others depending on their location and whether they were acquired by conquest. Parameter fitting has to enter the equation somewhere as these effects need to be quantified. Getting them right is obviously the main balancing problem but it shouldn't be too hard.
By the way, I'd really like the score to scale proportionally with population instead of a constant offset from modifiers, simply because that would encourage making large supercities to avoid penalties again. I don't think the rules are too harsh as long as you don't go out of your way to accrue all of the negative modifiers. With the rules you're familiar with (I've chance the core weighting now to scale with your era, so that large empires are easier to maintain later in the game) while settling only historical tiles you can keep four times of your core population in historical cities, which is quite a lot. Consider that now only the city's own tile and not the culture-covered tiles count, which makes things a bit easier as well.
What I really want to make destabilizing is conquest and occupying foreign cores*. Again, this is counterbalanced by the collapse to core effect which kicks in on an earlier expansion crisis level than complete collapse, so if your instability comes from this you'll lose the territories that make you unstable and should return to a better expansion rating.
On another note, I think it's also time to remove the player's immunity to complete collapses. The new mechanics should give you enough of a warning when you come close, and the "keep your capital" rule was rather exploitive considering you could just keep your army there.
*this reminds me that cores of not yet born civs should not count, as that makes no sense and would probably ruin the life Rome especially.
, -
penalties in Diplomacy, loss of OB/Defensive Packs/Trade agreements, loss of Apostolic/Congress/UN votes, DoWs
