Never played Bloodmoon, but was there only one small faction of Skaal on the island?

From what we saw, there was the Skaal (a single village) and a handful of outcasts. One of these was a budding necromancer, and the other three knew how to use Stahlrim as a material for weapons and armor.

Those latter three were kicked out because using Stahlrim as anything other than caskets is apparantly a blasphemy to the Skaal.

Yep.

One thing I noticed though is that the Skaal seem to be more Druidic than before, where they were barbarian animists. I wish there were quests in Dragonborn to feed people to ceremonial wolves.. haha.

I suppose I thought the Skaal would be almost equal in number as the Dunmer... But again, I never played Bloodmoon.