I'll be very excited to what you do with 7 Days to Die. Great and fun game, however it's pretty easy to make a compound that is pretty much 100% self sufficient and near impervious to attack. Especially in co-op when you can all be working on different parts of it.
The way your setting up your game system sounds awesome. Kind of like the Elder Scrolls games (at least from Morrowind on). Have the core, which is the basic rule set of how the game runs. Then have all of the content be a mod file. Makes it really easy to switch out and add stuff. And then people don't have to try and jury rig coding into your game. Cause when they do that, there are two or three groups of people that do so, making it so you need this mod adder/script for some of your mods, but then you need a completely different mod adder/script for the other. Oh, and if isn't obvious... I don't know 100% what I'm talking about, lol. I just kinda get the gist of it.