Too much confusion here.
Schengen area has more implications that just tourist visits. Schengen visas for longer periods come with a set of travel rights and permissions within the area, not in an equivalent manner (one cannot apply to study in Finland then ditch the program there and just start studying in Germany, for instance, in the same visa), but in regard of travel in the Schengen Area while on a long-term visa for another country in the area.
As for fretting about passport stamps, there is really no issue there: several countries do not use physical stamps of passports anymore (and the number is dwindling), but instead log the visa data in some central database and issue a letter. Upon arrival, the person registers with the appropriate agency (UDI, in case of Norway), where data from the visa is already stored, and then issued residence cards, civic registration numbers, foreigner registration certificate or any other relevant documment. Even the letter given to the applicant is just a duplicate of the registered data in their system.
I know it might sound strange for Americans or even British, but this is just how public administration is organized in most of continental Europe: there is a central registry of the resident population, and if you move (including citizens who always lived in the country, it is not just something for foreigners) you notify the agency responsible for civic registration. Immigrants might be subject to special registration requirements and in many countries, this is done at a sub-office of the main national law enforcement agency. Everybody must be registered and that registration automatically determines tax liabilities, official address for government communication (such as the address where any agency can officially reach you by presumption) etc.
It is just a different system. That is all. No need to lose sleep over it.
(Additional comment: stamps on passports of visitors to Schengen Area are also becoming obsolete as FRONTEX is becoming universal as intended. I have read many a worried traveler comment about "I arrived in Italy from US, they looked at my passport but did not stamp it". Worry not, as long your RFID-enabled passport touched the reader of the immigration official, your info was read and stored, stamps would be just reassurance to the visitor, not to the unified Schengen travel database official users)