David P James
The two concepts are really quite broken from an historical perspective.
In the game, crosses are about religious freedom, but in history it was really quite a mixed bag. Certain English colonies, notably Pennsylvania and Maryland, certainly offered religious freedom. But others, like Massachusetts and frankly most of New England, did not. The first immigrants to those colonies came to escape what they deemed to be religious persecution in England, but their leaders went on create some of the most intolerant statelets in Christendom. Non-church members often couldn't vote in elections. Dutch colonies were generally quite tolerant, and those traditions carried on once New Netherlands passed to English control. French colonies, by contrast, offered anything but religious freedom: New France was to be a pure Catholic colony and many French Huguenots ended up in one of Pennsylvania, New Netherlands or Cape Colony/South Africa. Spain was at least as bad, and Portugal probably wasn't much better (though Dutch control of some of their Brazilian colonies probably forced an increased degree of tolerance and freedom). At any rate, it's certainly not the churches and "Firebrand Preachers" of colonial history who had anything much to do with religious freedom.
The Liberty bells concept is just as bad, but differently so. The basic problem is that you, the player, represent a colonial governor. A lot of the time, the very person that a lot of colonists have a problem with is, well, you - often more so than the monarch himself. This comes down to a fundamental problem with the game: you're trying to lead an insurrection against the Crown that appointed you and which you represent by drumming up the support of the populace against their own monarch when you're the one interfering in their lives by telling them where to go and what to produce.
I haven't given much thought to how to deal with these, but a few things come to mind.
For one, the game has got recruitment the wrong way around: in the game, each next recruit "costs" more (in crosses or in gold) than the last. This is wrong: in history, it was getting initial settlers that was the biggest problem. Once a colony had become more prosperous and generally more civilized, it attracted more and more settlers, who made it wealthier, and so on. The English colonies had the benefit of the "push" factor of the Puritans' "persecution" in England to motivate a lot of Puritans to move to New England, but once there they got an economy rolling, which in turn attracted more settlers. The colonies of other nations never really had that kind of push, so they never got much of a draw going, either (though it appears that the Dutch East India Company did just about everything in its power to hamper the growth of South Africa as plenty of French Huguenots did settle there).
So it should be possible to model some kind of economic draw, perhaps based on the value of products sold in Europe. That can replace the crosses concept.
I really don't know what to do about the liberty concept. It's fundamentally flawed from an historic perspective, through and through.