Thanks for the excerts. I tend to agree that probably it's the sidebars more than the translation, though there are a number of 'easy read' translations that have got decent marks. There should be such translations for English learners.
Of what you quoted, this is rather peculiar:
For KJV; RV: Flee fornication,
Revolve New Century: 1Cor 6:18: "So run away from sexual sin."
New English B: "Shun fornication"
NIV: "Flee from sexual immorality"
Lattimore: "Flee from lechery"
Moffat; RSV "Shun immorality"
---That's all I have right at hand. I give Revolve/New Century low marks on that one; I say "Run away from New Century!"