Nothing in the following paragraph counts as licensing. You can take it to be commentary on the existing licensing.
All of my C# (code/SMAPI) mods are licensed with the MIT License, which is a permissive open-source license. The reason I license my mods this way is because I want people to be able to learn from them without worrying about permissions, and because this is one of the most readable open-source licenses. However, I would be sad if you took most/all of the code and re-released it yourself without substantial changes. I encourage you to push your creativity and create mods that are conceptually different than the ones you take code from. I want to contribute to an ecosystem that promotes growth and sharing, and I hope that my code can help you learn to create your own mods.