There were more "Skraelings" on the Island than the Beothuk, so it might not be so fitting to think in terms of their language specifically. The others, supposedly, and probably including the Beothuk, spoke an Algonquin sort of language.
IIRC (this tag applies for all that follows in this post), the 'Skraelings' of Greenland were an Innu speaking people, whereas the "Skraelings" of Newfoundland are thought to have maybe been (oh the uncertainty) the ancestors of the Beothuk, which were Algoniquin. Indeed I don't think there is much evidence to say that the two 'Skraelings' were culturally related except for the fact that the Norse gave them the same name. Also there is no reason to suggest that the Beothuk came to Newfoundland before 1000, and at that time the First Peoples settled on Newfoundland could, in fact, be culturally Innu.
There are also the Dorset preceded the Innu in much of Northern Canada and are known as the "Tall People" in Innu oral history. They had a distinct culture though it is thought that they were driven away by the Innu who were better suited for the Artic climes. The term 'Skraeling' however dennotes the lighter build of the Innu in comparison to the reportedly bigger and physically stronger (though techonologically inferior) Dorset. I don't think that the Dorset should come into play here.
I don't think a mixed Vinland-'Skraeling' culture would retain the Norse language in the same way that the Spanish colonies did. If Vinland is to be truly isolated from Europe the lack of continual contact suggests that the Norse would be on their own, forced to adapt their ways to that of their new Wifes, Fathers-in-law, ect whose local knowledge would be far superior to that of the Norse. Words for natural formations, animals, plants, ect would naturally be Kalaaleq in this envisioning of events. Perhaps the language would be closer to the one used by the Metis in construction--that is French Nouns and Cree Verbs (replacing Norse for French and Innu/Algonquin for Cree, or visa versa).
To use Kalaaleq we'd have to assume that the Greenland colony also merged with its native population in a similar way, and that the Skraelings of Newfoundland were culturally related to the Innu 'Skraelings' of Greeland. The Beothuk, in this scenario, never established a foothold on Newfoundland--or if they did we could see them as a poorly integrated minority within the Kalaaleq nation marked by sporatic events along the line of the various revolting minority ones that exist for European nations.
The Norse names would satisfy the requirments of options A or B, but not C, for which I think we need to use a Metis-esque construction. While Kalaaleq may not be the best, as it is used by the Innu of Greenland to this day as a self-identifier and would would require the Greenlanders to have integrated into the Innu society there and for these peoples to have migrated and then dominanted the Newfoundland colony, which also integrated with a culturally similar Aboriginal people.
Again, all this is based off of memory spiced, occassionaly, by a quick fact check to Wikipedia which is not always the best place to do fact checks.
Cheers.
