Just two other (and for me, final) points: To add an "a" in English translation to bring out the sense of the Greek, even when the Greek grammar has no "a" but is without the Greek definite article, is a standard translation practice. All Bibles do this, when the translators feel it is necessary. Maybe not at John 1:1, but certainly elsewhere. There is nothing wrong with this, because English is not Greek, and to properly translate Greek sentences into fluent English, words may have to be added for proper English understanding.
The other thing is that Jehovah's Witnesses do not actually deny the divinity of the Lord Jesus Christ, according to what is written in appendix 6A of the New World Translation Reference Bible (1984). They admit that Jesus is called theos, "god/God," in the New Testament and "mighty God" prophetically at Isaiah 9:6. The objection is not to presenting Jesus as divine or deity, but to the claim that Jesus is God Almighty or the same as the Father in every respect, as Trinitarians claim.
Being a created being does not detract from divinity in the Hebrew world-view, which would have been the apostle John's primary world-view as well, inasmuch as angels are also created, divine (i.e., spirit) beings. For example, the angels are called "sons of God" and are represented in Hebrew thought and theology as part of a divine counsel. A problem I see with viewing John 1:1 as Trinitarians do, is that it would make the apostle John a Greek philosopher rather than originally an adherent of Judaism -- even the diverse Judaism of the first century.