I understand that a long thread like this can make you confused but, as mentioned before, the traditions were mentioned in passing as a reference to common Swedish culture today (one of the ethnicity criteria). The fact that they perhaps build on earlier pagan traditions, very likely common within the whole Germanic area, is merely interesting.

As for my source, I would still say that self identification based on research is much more legitimate than anything you can come up with. Quoting one sentence from the Finnish Ministry for Foreign Affairs Webbpage, based on some junior civil servants (webb-editors?) personal opinion, is not more legitimate than creative interpretation of a Swedish medical study (which actually does'nt support your claim).  

Selective quoting out of context in fact seems to be your speciality, regardless of the source. Besides the portion of text you quote regarding a small area of Swedish Finland, you did notice the bold text that forms the summary of the text? "Det svenska området omfattar Nyland, Åboland, Åland och Österbotten. Området är i stora drag oförändrat sedan 1100- och 1200-talet, då högmedeltidens stora bebyggelsevåg förde svenska nybyggare till de obebodda kusttrakterna i Finland" (The Swedish area incompasses Nyland, Åboland, Åland och Österbotten. The area is generally unchanged since the great middle-age migration that carried Swedish settlers to the uninhabited coastal areas of Finland).

As for the paragraph on movemement that you quote a part of, it concludes with: "Flyttning över den (språkgränsen) har förekommit i alla tider, men har blivit en företeelse i stor skala först i vår tid" (Movement over the language-border has taken place in all times, but has become a large scale phonomenon only in our time).

Your comparison to Ireland is interesting and in your mind perhaps even relevant. The Irish situation is however different, e.g. the English occupation actively surpressed the Irish language, culture and heritage. Something similar did not take place in Finland. In fact the Finnish language was actively developed and promoted by Finland Swedes (initially due to academic interest and in the 19th century as a bulwark against Russification).
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