I have an idea for a mod (described here https://www.reddit.com/r/humankind/comments/ri3mb3/religion_stars_and_affinity_suggestion/) 

I want to add a new era star for religion, which is awarded for having x followers. This would fix the balance issue wherein "tradition" is the only ideology axis that isn't directly beneficial to any victory condition, so the player almost always chooses "progress". After that, I would add a new religious affinity and new cultures with the affinity, as described in the reddit thread. Right now I'm just trying to learn the basics of the modding interface, so I have some questions:

1: Is adding a new era star even possible with the modding tools? I understand that through C# all things are possible (this bepinex project seems like the closest anyone has done so far to what I want https://humankind.mod.io/humankind-configurationtool) but I want to know if I can do it "non-invasively" before I try to teach myself bepinex or (gods forbid) the game's sourcecode

2: If the answer to 1 is yes, is there a good guide anywhere to getting started? I've read the blogpost where they change the Howitzer, but I'm curious if anyone has already written a guide on more advanced modding

3: If the answer to 1 is no, is there a good guide to bepinex?