Your guess is correct. The short answer for this is that articles in English are weird (for a Germanic / European language).
The slightly longer answer is that in the Middle Ages Britain got repeatedly invaded by Scandinavian peoples (these days also known as "Vikings"), by some speaking Norse or German dialects, but a bit later and most notably by the French-speaking "Normans". In the process English changed quite a bit and became increasingly creolised. One effect of this was that gender as a grammatical category lost a lot of its markers (and vanished more and more over time). Of the former three different articles of Old English, "se" (formerly masculine) survived and later changed to "the", while "þæt" (formerly neuter) became "that" and "sēo" (formerly feminine) might have turned into "she". Since this also meant that articles had essentially lost one of their core functions, namely that of marking gender, they somehow also changed in other regards in the process.
I don't know how wild nature has to be to be counted as the WILD/the WILDERNESS, but in norwegian there is definitely a difference between naturen og villmarken (though they overlap).
A bear might live "i naturen", but also "i villmarken". But "villmarken" is farther from civilization.
Wild is short for wilderness and has a overlapping but slightly different meaning than nature. It means untouched nature. You only get that deeper out. Villmarken sounds much closer to wilderness based on what kim-gab said. Translating naturen as th wild is just wrong. I don't understand why so many native English speakers especially Americans don't know what words mean.
I think the difference lies in the subtlety of meaning, which in English is somewhat obscured because we can use 'to live' in both contexts. The following example should show English has the subtlety although it doesn't necessarily use different words to highlight this difference.
English: I live (am alive)/ (exist) = norsk: Jeg lever. *English: I live (reside, have a house, etc.) = norsk: Jeg bor.
*In both English and norsk the second example given needs to have some kind of qualifying component to make a complete sentence whereas the first does not.
Yes, I think until you see a pattern that makes sense to you, then use 'å leve' as a first choice. It is possible the following may occur:
Bjørnen lever ute i skogen, men den bor i hula. (The bear lives (exists) outside in the forest, but it lives (resides) in the cave).
I may have written the example incorrectly på norsk, so I apologize for any error.
It does, if you're doing a component-by-component gloss; however, in a good translation it is necessary to fit the rendering of the sentence to the target language. It would be unnatural to say "in the nature" in English, where as "i naturen" is natural in Norwegian. What's important is that the idea (i.e. semantic value) of the statement is communicated.
Because it is not how we'd say it in English. "Nature" in the sense of the natural world, does not have "the" before it.