I was looking at this game and thought it would be cool to get into the modding scene for it, however after reading a post, I am a little confused.
Would I need to purchase the developer access to be allowed/able to mod this game?
No, but it might allow you do better request for features you want, and/or directly pull request them to us.
You can mod most of the items/objects in the game right now by editing the files in the Mods/ folder. We still have some work to do to re-enable client side mods (item icons, new objects, new animals, etc) but that will be coming.