Around 10% of the Icelandic population are immigrants, which hardly qualifies as a low level. You could easily call it "wild, rugged" if you live in the highlands, but where most people live there's no stronger feeling of ruggedness than in any other northern European city or town.
High prices are a barrier, I'll give you that, but the winters are milder than you'd think (we can thank the Gulf Stream for that). The language is definitely a barrier, but culturally I wouldn't say it's a big hurdle.
No, and I guess I should not comment based on a shallow understanding, as I clearly got some things wrong. The upside is that the replies like yours are informative and factual.
What percentage is first generation low-skilled laborers outside of mainstream Icelandic society, or integrated immigrant citizens in all walks of life?
There's a big difference between the two.
There's been a consistent increase in immigration since the mid-90s when Iceland joined the EU's free movement program. This pattern continued even though the 2008 crash (accelerated if anything).
Iceland's the 6th richest country in the EEA by GDP PPP. There's a general trend in the EEA of people moving from east to west for better pastures, Iceland's biggest foreign-born population is Poland, followed by Lithuania.
1. https://hagstofa.is/utgafur/frettasafn/mannfjoldi/innflytjen...
The big difference would be as to whether immigrants are welcome and integrated, or merely tolerated as necessary evil unskilled laborers.
I expect that the real barriers will be language and cultural - i.e. how to integrate, not just make a living. It's probably easiest if you come from a Scandinavian country.
The other barriers are the the high prices and the arctic winters.