I guess you're probably right. But considering the countries border each other I guess that the race is quite similar.
Its not true, viking was a form of activity, a career, and something you did, not a ethnic or geographical description as some might think. Even though the origin of the word probably derives from the fact that vikings often were in their boats in Viks(near the coast), while waiting to strike, or just waiting for the weather to get better, as mentioned in several of the sagas.
You can say a person is A viking, as in, a raider that use ship, mostly a hit & run tactic which the Scandinavian ships were perfect for as they were the fastest ships in Europe. But a person can also say "im going viking".
A example in Norwegian: Eg dro i austerviking,
In english that is "I went eastviking" It means, that you went to the east, in viking(raiding). Plundering eastern europe.
The sagas tell of danish vikings, swedish vikings(svea, g?ter), Norwegian vikings, saxon vikings, also vender(todays poland) vikings. Even though non-scandinavian vikings were rare, they probably were'nt able to compete due to inferior ship-technology.
A lot of people have no idea how to use the word viking. And what it actually means. Its more often used wrongly then correct.
Personally ive read all the sagalitterature that does exist in Norwegian. Then you get a good picture of these things.