While Minecraft mods are usually pretty safe, there are always risks involved with downloading and installing files that you find on the Internet. Some of the most important concerns are: The mod itself might contain malware, spyware, or a virus. Are mods free? Many mods are free and range in scope from smaller changes here or there to entirely new items, characters, maps, or missions. Other mods may add expansive community-created content equaling hours of new gameplay and storyline, or even an entirely new game built from the ground up.
Do mods damage your computer?
Mods can't break your computer. Poor ventillation, too much overclocking or faulty hardware can. Not to mention the one you linked is a parts mod, it doesn't even have a binary (.exe, . dll) file that could be malware. Do I need OptiFine for shaders? For most Minecraft shaders to run, you need to have OptiFine installed with your Minecraft. Make sure to read the requirements and other mods required before you install a shader.
Are there hidden chests in villages?
Villages. Villages are the most commonly generated structures in Minecraft. You can find them in various biomes, except jungle, mesa, extreme hills, and ocean. Treasure chests usually spawn inside houses, but the most common building to look out for a treasure chest is the blacksmith's shop.