Hello,
I am having trouble adding any items from a weapon set (such as Nicoroshi's Creations) to a plugin of my own. I am just trying to test out weapons and view them on my character without having to do the quest or find them. The items simply do not show up when I arrive at the location in game (the location I placed them in using TES Construction Set). However, I tried it with a custom staff, which I then ALTERED THE ID so I could add the enchantment I wanted. This staff DID show up in game and I was able to use it. I will test other items by changing their forms maybe tomorrow, but was wondering if anyone else had experienced this before and had any solutions/advice. Thanks!

Any changes you make to objects not originating from the active plugin or loaded masters will be discarded when you save the plugin.

The exception to this is, as you have seen, if you create a new object. The new object will be part of the active plugin, and so uses of it and changes to it will get saved.

Thank you VERY much, this has been bugging me for a while now. Is there a way to add another plugin as a master file?

Yes. I'll give you the easy way.

Download & install the Construction Set Extender. It's an OBSE plugin by shadeMe. You'll also need OBSE v0020 or higher, if you don't have it already. When you use the CSE, any plugins you load alongside the active plugin will then become masters of that plugin next time you save it. This means, of course, you'll not want to load up extra plugins unless that is your goal.

Alternately, http://cs.elderscrolls.com/constwiki/index.php/De-Isolation_Tutorial is the CS Wiki entry for mod de-isolation (which is what you're after). You can learn from this how to convert plugins to masters and vice-versa, so you can accomplish your task without the CSE.

You should also keep in mind that when you make your plugin dependent on another mod, you'll need to always have that mod for your plugin to work. For me, this is generally enough motivation to create new forms rather than create dependencies, but you can choose whichever suits your style better.

Thank you very much! A good solution for my first experience on these forums =]