Many years ago we were taught that the vikings were little more than barbarians whose first act upon meeting a new group of people was to hit them with a sword or axe to see if they were gods. We also learned that they cared nothing about personal hygiene, education, modesty or authority. It would be interesting to hear if any of that is considered accurate these days.
After that first violent contact, they often settled down and adapted to the surroundings. Normans are really Vikings who invaded Northwestern France, picked up the language, and within a few generations crossed the channel to become the rulers of England in 1066. Ironically, most of the Latin words in our language came to us via Frenchified Vikings (Normans).
Doubtful; for the most part seafaring Vikings were traders, which why they set up their colony in North America (they traded metal for walrus ivory with the natives).