LittleToe:
I think we have much in common. I agree with you that we cannot be certain of the meaning in Genesis 10:9. To translate it "in opposition to" is a legitimate translation, and I believe it is the correct one, but it is not the only one. In fact, Brown, Driver, Briggs suggest the meaning here is "in the sight of" i.e. in the estimation of and include Genesis 10:9 with :
Genesis 7:1 - "...'you (Noah) are the one I have seen to be righteous before me among this generation.'"
Deuteronomy 24:4 - "...that is something detestable before Jehovah."
Nehemiah 2:5,6 - "After that I said to the king:'...if your servant seems good before you...'. So it seemed good before the king..."
Esther 5:14 - "...So the thing seemed good before Haman..."
Proverbs 14:12 - "There exists a way that is upright before a man..."
This is true with many passages in scripture or any translation from one language to another. The translators have the task of selecting the most accurate word or expression to convey the intention of the original writer and not all will agree just what that is.
But while I do not fault the NW Translation Committee on this verse I do agree it did not stick to its mandate of a literal translation when replacing 'Lord' with 'Jehovah' in the NT. No extant copies of the NT contain God's name and so this goes beyond the remit of a literal translation in my opinion.
Earnest
Pax tecum et cum spiritu tuo