..First off, the "good vs evil" of which you speak is being preserved. It's simply under a new name; The new alignment axis is exactly what Good/Evil is now. It will not change in game (or not in any significant, simple way; The absolute only thing that can affect it is an AC affecting action, and only if we want it to)...
Names are important. They define how something is perceived from the outset. I fully understand "Alignment", at least from the classic AD&D perspective. I also understand the social component and think that it's a "Good Fit" for the game.
But, the game's "Sides" were not initially designed that way. Basium was brought up. Basium is a force of nature, a contradiction when it comes down to defining an Alignment. There is one moral force guiding Basium's actions - Defeating Demons. The social aspect is, generally chaotic, preferring to pursue the moral goal through war and destruction with no chance for Peace and the rule of Law.. But, neither apply, here. There is no Law that would effect Hell.
The game conflict for the player is to win against several opponents in any number of ways. The setting, however, has a broader conflict of ultimately resisting or aiding the advances of Hell (Evil) on your way to victory. But, that isn't a victory condition, just a great backdrop for the setting. Consequently, the sides are designed with that setting in mind. Good vs Evil is an intrinsic part of the setting, if not the gameplay itself. And, the setting is something that has to be protected in order for the game's potential to be fully realized. That's all I'm saying, there.
As you said, many games have a heavy Good vs Evil theme... And most of them do not actually call it Good vs Evil. Alliance vs Horde would be an example here; Neither is actually good or evil, both form distinct factions pitted against each other. We will have this theme... We simply choose not to call it by the same name.
But, the setting is different. There isn't much of a noble story behind Hyborem and the clear lines between Good and Evil are intentionally blurred, by design, in order to present equally appearing factions for the players to choose from, each with a point of view of the broader conflict that is translated from their own race's perspective. Good and Evil are intentionally "Grey" amongst Sides. In WoW, back when I used to play for far too long, there really were only two factions that could be classed as "Evil" - Alliance Humans and The Forsaken. But, even the Forsaken could be excused, a little bit. Being dead can be a downer.. Human treachery, on the other hand, could not be excused! FOR THE HORDE!
As I hinted at in another thread, Neutral alignment will be difficult to maintain... and quite rewarding. It's not something I've discussed much with the team, but part of the plan is for each alignment to grant a specific bonus; Lawful may grant discounts to city maintenance, while chaotic may grant unit production bonuses. Changing an alignment would not carry a penalty, but would result in gaining a different set of bonuses, much as you said in your post.
Be very careful that the new incarnation does NOT turn into an Alignment Game, where the actions of the player are completely dictated by their Alignment.. or desired Alignment. Any time you artificially constrict the actions of a player in a sandbox game, you put them on a rail just as bad as an invisible wall. Sure, a player can decide to do all sorts of things during the course of a game. But, a VERY limited number of them should dramatically change the foundation of "their game" during that play period. Balancing that with the need to predict the unexpected in a game is very difficult. ie:
I have choice X to make between A & B. "A" will allow me to continue with the Alignment that I have been playing, reinforcing, building around, and enjoying for the past four hours. However, "B" will prevent my Civilization from being crushed by the SOD that is currently marching towards my Capitol. But, if I choose B, I don't get to play the game I've been enjoying and have to give up that enjoyment to find new enjoyment in this new Alignment and figure out how to proceed from there.
To combat that problem, most games with fluid Alignments allow for only gradual change. IOW, it comes from a series of decision points given to the player, each decision ranked fairly equally, with a few large, but clearly evident, decision points presenting themselves so the "slow" player gets the gist of what it actually is that they're deciding they want to be and how the game is going to facilitate that. RiFE is a very dynamic game, with situations changing rapidly until the game "matures." (ie: Once the map is fully revealed and most settlements have been done, the game is generally "Mature" and late-game elements, like Basium and Hyborem along with the Armeggedon Counter, start to grow in importance or get introduced.)
IOW, for what could be a six to eight to 12 hour game that is highly dynamic (much more so than any single-player RPG one could care to play, Oblivion included) setting up decision points for Alignment could be very difficult. The play may vary dramatically over the course of that game.
I'm not a big fan of Stardock's games as having a lot of "depth." So, don't mistake that here. But, a good example of trying to set a player's Alignment in a long, dynamic game can be found in Galactic Civilization's 2. The player has a few decision points thrust at them which have relatively little impact on the gameplay, itself. Yet, in the broader scope, it somewhat effects the player's abilities with diplomacy and how other races supposedly "view" the player. In reality, in the game, it really doesn't mean much of
anything... It's simply a "Roleplaying Element" with not a heck of a lot of weight to it as far as gameplay goes. In fact, in many games like that, Alignment has little effect. Or, far worse than having little effect, Alignment can railroad a player's choices that could have a dramatic impact on their game experience. (I remember one RPG long ago that ruined your shot at obtaining a nifty item if you had chosen one of the polarized responses in a decision point that took place in the very early game.)
So, what some people do is give a player an "Oops Factor" by making decision points that are very heavily weighted have little impact on any present gameplay. So, you're never forced with the Ultimate Question when you are least free to make an honest choice. Other "Oops" factors are ways that one can push the odds in favor of a particularly desired Alignment, in case the Player chose.. poorly.. early in the game. So, making donations to a temple, building a particular shrine, visiting the same sick kid and bringing them medicine.. over and over and over.. etc.. Will count as weighting the odds in favor of whatever Alignment the player wishes to "roleplay", despite the in-game decisions that the player could have chosen by mistake or necessity.
So, we've actually discussed quite a few of the things you brought up; We feel quite satisfied with the direction we're going. No, it will not be identical to FfH, but it will have features that serve the same role.
Oh, I didn't expect a turnaround, just an opportunity to blurp up my thoughts on the matter.
In closing, because of the Setting in RiFE, I feel that Good, Evil and Neutral need to be very firmly rooted in the role-playing aspect of the Game. That includes Side choices as well as Win conditions and a very few, inconsequential, actions as "Decision Points" in the game. I also feel it is important to clearly define the Good and the Evil, as well as the Neutral, but still allow for sandbox play.
The mechanics of the game are meaningless in Good vs Evil games. (At least, generally.) It's primarily a role-playing decision and it needs to be approached in that light. Because of the dynamic gameplay experience of the game, making them much more than that will be extremely difficult. Sometimes, the player's imagination is the tool that you must rely on the most. And, that can not be hardcoded.