I am not an expert modder either, but I can help you with a few tips. Chests are under Worldobjects>Container, choose one chest there and right click to duplicate, then rename the duplicate (right click>rename). Once you rename it, double click on it to open its properties. In the middle of the window you see the item list, right click and and add "new" and choose the item you want to add the chest in the drop down menu under Object. An advice: I didn't check the mod you sent, but if the mod is .esp file, you may have difficulties to make the items appear, because you cannot use in your .esp files from other .esp's. I generally convert the resource file into an .esm using TES4 Gecko. 2. You can make the key under Items>Key. Right click and add a new key. Then put your chest into the render window and double click on it. A reference window will open up, click on "Lock" tab, tick "Locked" and choose "requires a key" from the drop down menu. As key choose the key you made earlier. You can then put that key in the inventory of the NPC you want. Hope this helps, Happy modding