As I said, since we don't have any samples of the languages themselves, there's no "correct" interpretation, so yours is just as good as anybody's. :)
Personally, I don't like drawing parallels between the languages of Earth and those of Golarion, as I think they're completely different, and my "family tree", so to speak, doesn't match well with that of Earth languages. Therefore, it's inevitable that some languages that are not closely related in real life end up being so in Golarion. However, your list is very good.
Here's the list of what I think the features of each language in the Inner Sea are like, so you can have an idea of what I had in mind:
Taldane (spoken in Taldor, Absalom, Lastwall and, unofficially, in the rest of the region) = elegant and refined, like Victorian English, but at the same time concise and practical, like today's English.
Chelish (spoken in Cheliax, Isger and Sargava) = a beautiful language, very good for song, poetry and rhetoric, much like French or Italian. Isger and Sargava have their own dialects.
Andoren = very concise language, with many quirky sayings; not as formal ad Taldane or Chelish. Like modern Italian.
Galtan = a "fiery" language, very passionate. Like Spanish or French.
Molthuni and Nirmathi = very similar to Chelish, but with enough differences to be a separate language. They're the same language, only with two different names, depending on the side of the war you're on.
Varisian = another passionate language, full of innuendo and subtlety but also more vulgar than most (especially in the mouths of the Sczarni).
Ustalav = a slow, phlegmatic language, like today's Polish or Russian.
Drumish = a language almost as subtle as Varisian, whose family it belongs to, but not quite as exuberant.
Skald = a language both harsh and poetic, like Old Norse.
Irriseni = Irriseni and Skald split only comparatively recently, so they're still very similar, but not enough to warrant intelligibility between them. The language of the jadwiga is totally alien and doesn't fit in any Golarion language family.
Hallit = a throaty, harsh language, poor in rhetorical embellishments but very direct.
Mendevian = somewhat long-winded language, but otherwise unremarkable.
Numerian = throaty like all Iobarian languages. It's the language with the most "modern" lexicon.
Brevic = another harsh language, but more "sophisticated" than the other languages in the Hallit-Iobarian family.
Razmirani = similar to Brevic.
Avistani Elven = beautiful to hear, but somewhat complicated in grammar.
Five Kings Dwarven = full of complex consonant clusters, but beautiful in its own way.
Alkenstari = difficult to pronounce like most Dwarven languages.
Orcish = harsh and unsophisticated language, poor in vocabulary. Some linguists want to link it with the Goblinoid language family, but for now it remains isolated.
Shadowtongue = strangely beautiful language, probably because of the influence of Infernal.
Draconic (spoken in Hermea) = a very complex, difficult language which nonetheless affords a great deal of elegance.
Qadiran Keleshite = beautiful language, useful for both poetry and prose. In the courts they use Classical Keleshite, which is the official language of the Empire.
Katapeshi Keleshite = very direct, very no-nonsense language.
Osiriani = beautiful and rich language. It's the official language of all the courts of northern Garund.
Thuvian = more a motley collection of dialects than one language.
Rahadoumi = complex language, but one of the best for philosophical dissertation. It is spoken in Rahadoum and on Mediogalti.
Nexian = very complex language, but the best for talking about magic.
Gebbite = somewhat conservative language, retaining many archaic forms, and heavily influenced by Necril.
Jalmeri = beautiful in sound, complicated in grammar, it's still less complicated that most other Vudrani languages.
Polyglot languages are hundreds and I can't go in detail about all of them. Some are tonal, others have rare sounds like clicks.
Shoanti languages are famous for their strange sounds (ejectives mostly), and complicated grammar.
Here it is, sorry for the long post. There are dozens of other languages spoken in the Inner Sea Region.
Hope this helped.
