Right, I can understand why they wouldn't be happy about that. I'm not even sure I want to publish this book if I ever do finish it, but if I do, I'd definitely have to look further into this issue.
That makes sense-- I can see why people would want to copy from Tolkien's work; I want to myself often, and it's hard not to. I must say, though, that I don't intend to use any names that are in Tolkien's writings, like 'Eldar' or 'Mithril', merely names and places I would translate into Quenya. For an example, the land of the evil guy in my story is called Sunderland in English, but the Elves would call it 'Narcanor'-- 'Sundered land'. I don't think 'Narcanor' is used anywhere in Tolkien's, or anyone else that I know of's, writing. I'm hoping to avoid copying too much from Tolkien, even though he is a huge influence. Hopefully that makes things a little clearer.