My friend, who's a Ukrainian citizen, initially applied for a short-stay visa Type C, from the Norwegian embassy, with the intention of attending a conference in Norway. The validity is from March 7 - March 15, 2017 with 22 number of days. The conference is just from March 7 - 17, 2017 (10 days), so she has more days with that visa.
She decided to visit her relatives in Stockholm, Sweden after the conference from March 20 to 26 (7 days), and then go to Paris for 5 days satisfying the 22-day validity of the visa. (She did not declare the Sweden and France trip in the visa application, will that be okay?)
The New Plan:
Her thesis defense at her university will be between the dates of the conference. Thus, if she won't be able to reschedule it, then she will have to skip the conference, but she still wants to use the visa.
Now, she will enter the Schengen area on 21st of March, instead of 7th and through Sweden. She will visit her family in Stockholm first on March 21, 2017 until March 28, 2017 (8 days). Go to Oslo, Norway as a tourist and not as a delegate for the conference anymore, for 9 days (March 28 - April 5). And then go to Paris for 4 days(April 5 - 8), and Amsterdam for 3 days (April 8-10).
Will the immigration officers find out that she changed her purpose as a tourist? (even if she shows proof of accommodation as a tourist, letter of invitation from her family in Sweden, and plane tickets following the new plan?)
Will she be allowed to go to Sweden first and stay there for a week before spending more days in Norway?
Does she really have to spend more days in Norway because the Norwegian embassy issued it?
How will authorities know how many days you spent per Schengen country if there are no border control within the Schengen area?