Whether Frigg and Freyja are two different goddesses or the same goddess may depend on whose version of the mythology is involved.  Most of our surviving sources are Icelandic, and in those, yes, they are distinctly different.  However, German inscriptions seem to indicate that continental folks considered the two equivalent.  It’s hard to be completely certain, as German paganism wasn’t as well documented, or at least the documentation didn’t survive, as well as the Icelandic and some Danish material.

What I find more fun is that Sunday and Monday are also named after Germanic deities:  Sunna, the goddess of the sun, and Muni, the god of the moon.  So while the concepts of sun and moon were translated, up North the genders are switched from the more popularly known Mediterranean mythologies.

I’m not particularly convinced of the material in When Santa Was A Shaman, the main popular source for “he was based on Oðin”.  (I get really sick of the constant half-assed scholarship in the pagan community, incidentally.)

Finally, the Icelandic word for Saturday is Laukardag (Lørdag in other Scandinavian countries), which means “washing-day” but I’ve seen some scholars (sorry, don’t have citations at hand) suggest could have been Lokadag (Loki’s day), as similarly misrule-oriented as Saturn in Roman myth, but altered in Scandinavia and avoided in England, for similar reasons why the recently-converted Germans decided to say Mittwoch instead of invoking Wotan every time they talked about Wednesday.