[fwipsy]

They had their own culture and technology, but that's not the same thing as being civilized. It also includes being, well, civil. Raiding and pillaging their neighbors is not civil.

> ascribing sone (sic) kind of higher ethics to christianity is also quite a stretch.

This is subjective. Even if you disagree with Christian ethics, and even if they were frequently violated, becoming Christian still could have reduced Viking violence against their neighbors. Shared culture would improve trust and encourage alliances and trade.