"Derived from King James Version": Wikipedia's entry says so, but what is wikipedia's documentation for that claim?. What does the author say? Was the author's background? Did the author have a knowledge of the Biblical languages? He was the Dean of a School of Religion. Was he dependent on the KJV only? Have you compared the TCW with the KJV?
I would go with what the author says, that it is personal devotional paraphrase, after the style of Philips, Taylor and Peterson. The author states it is not a study Bible.
Yes, you are correct. The Clear Word is a devotional paraphrase and in no way considered any kind of "official" anything for SDAs.
And while there is a good possibility that the author may have referenced the KJV in some instances, many of his texts do not match the KJV reading but more closely resemble the corrupt Alexandrian text.
For example, the Clear Word renders Revelation 8:13 as "As I looked, I saw in vision an eagle soaring high overhead, crying with a human voice, 'Woe, woe, woe..."
There is not a single Bible from the pure line of manuscripts that uses the word "eagle" in this text. This use of the word "eagle" is solely linked with the corrupt manuscripts from Alexandria (from Eusebius and Origen).
All the manuscripts from the pure line as well as all the Bibles translated from them (KJV, Geneva, Coverdale, Matthews, Tyndale, Olivetan, Diodati, etc. etc.) use the word "angel".
This tells me that the author of the Clear Word was being influenced, at least in some degree, by either corrupt Bible versions or corrupt manuscripts, and that his paraphrase is not "based on the KJV". So while I'm sure that the author probably had the best of intentions, I would not consider the Clear Word accurate.