Where did you read these articles indicating it would be easier as a self employed person? Afaik, there is still no such thing as a self employed visa for Iceland. If you read the work visa options on utl, all of them list an employment contract as part of the paperwork requirements.
http://utl.is/index.php?option=com_cont … 〈=en
As for creating an Icelandic company, I know it isn't hard to incorporate an ehf if you are in Iceland, but I'm not sure how it works if you don't have any Icelandic registration yourself. I at least don't know of anyone who moved this way.
Fwiw though, the definition of highly specialized may not be quite what you think. Iceland is a pretty small country that doesn't tend to attract people at the top of the pile in the business world. Your wife may be able to find a company who will hire her. Based on years of experience doing the paperwork for a work visa myself, it isn't too complex or expensive for companies to hire non EEA employees.