Please be advised that "attack" is not my intention. Sorry if I gave you that impression.
Thank you for saying that. I did get that impression. It is often modus operandi that JWs use where they start attacking the person in order to avoid the actual issue being discussed, especially when backed into a corner. I sort of felt like that was happening (not that I backed you into a corner... far from it... I'm not seeking to win any argument... just stating my position on this particular matter.)
You insist that adding "other" is totally wrong at Col 1.16. To be honest, as you pointed out, it is not required
in the translation of the verse. The context already places Christ
under God in the epistle. At the same time, it is not absurd to include
it.
@menrov makes a valid point.It bible translators believe they need to add or remove a word, for
whatever reason, they should explain it with a proper footnote so the
reader understands what has been done and can decide if he agrees or
not.
I would accept this in a translation. It's one of the reasons I like the NET Bible, even though it is not the best translation. They have tons of footnotes explaining various ways something can be translated. In the case of Col 1:16 in the revised NWT, there is no footnote at all and "other" is not in brackets, misleading the reader to think that it was in the original text. In Rbi8, there is a footnote, but it has nothing to do with why it's there. There are brackets around "other", which is at least something because they explain in the Introduction: "Single brackets [ ] enclose words inserted to complete the sense in the English text. Double brackets [[ ]] suggest interpolations (insertions of foreign material) in the original text." No such thing exists in the revised NWT.
As far as Bible translation goes, there are different methods of translating that basically fall into one of two camps: exegetical or eisegetical.
"While exegesis is the process of drawing out the meaning from a text in accordance with the context and discoverable meaning of its author, eisegesis occurs when a reader imposes his or her interpretation into and onto the text." (Source: https://en.wikipedia.org/wiki/Eisegesis)
The NWT was translated in an eisegetical method. The bias of the JW religion shows throughout. I am NOT saying it's entirely wrong, just as I'm not saying that all JW doctrines are wrong. Some are. Some aren't. I AM saying they have decided to impose their own doctrinal beliefs into the translation, which is why they strongly frown on the use of other translations in their meetings. They quote from other translations when it suits them. If I were to start using the ESV or the NIV or some other translation at the meetings, I'd get a stern talking to by the elders. Of that, you can be sure.
Col 1:16 really is an example of eisegesis in translation. I happened to personally agree with this particular teaching, but I do not agree that it belongs in the translated text. At least, as @menrov wisely suggested, not without a footnote explaining why they put it there.
If you get some time, you may want to view this video. It's lengthy, almost an hour. But I found it fascinating as he describes the various purposes of Bible translation. I don't necessarily agree with his conclusion, but the video is somewhat informative: https://www.youtube.com/watch?v=IYc2KjRKlKU