Awesome! I just have a few questions about the general layout of the civics. After that, I can help with what civics I think there should be and what their effects are.
1: Are you going to stay within the general area of the original civic trees (government, legal, economy, labor, religion), or will you make different and/or more categories? IMO there should be more, such as military, what society emphasizes (efficiency, military tradition, things like that), etc.
2: Approximately how many civics will there be per civic category?
3: Approximately how advanced will societies become. I know they will start out with a scavenger/survival situation, but will they reach or even surpass the economic, legal, etc. systems we have today?
4: How complex do you want civic effects to be? Mods like RoMK have civics with a lot of effects, while in the original game civics were more contained. Personally I prefer the complex, RoMK version, because the civics you choose have much more of a significant impact on your civilization.
I would also love to play test the mod.