You've got the gist, but North Korea does use tonnes of Sino-Korean words, which are like words of Greek and Latin origin in English. You can't simply eliminate such words from the language altogether. What you can do is to favour pure Korean words over Sino-Korean when coining new terms or standardizing terms for technical usage. So North Korea might use a bit less Sino-Korean than the South (I'm not even sure though, because there are other factors such as loanwords in South Korea displacing Sino-Korean words there). But this makes barely a blip on the language as a whole since so many basic words in Korean are Sino-Korean. Even most North Korean terms you're ever likely to hear are Sino-Korean: Juche, Son'gun, Chollima, Rodong missiles...

To add on to this: In South Korean newspapers you'll often find Hanja (the original Chinese characters) on news sites or in the paper or even on the news. It may be simply to clarify a phrase, or for when someone has passed away, there's a character for that. So South Koreans may not know a lot of Chinese characters, but they know the basics and they are quite aware where many words come from-- In North Korea to emphasize their Korean-ness they have little to none of these Hanja anywhere, they don't learn it in school like a South Korean child would, either.

On top of this, you'll find that those English loanwords are almost nonexistant in North Korea. Where South Koreans will simply say "Ice cream", North Korea has the word "얼음보숭이" which literally translates to "ice fluffly thing".

There's also differences in the speech styles (a very complicated and extensive topic in itself) and verb endings. NK prefers some styles where SK prefers others-- But like it was said farther up, the difference really comes down to something like US/British English, obviously different but still very mutually intelligible.

Actually, they do teach Chinese characters in school in North Korea; it is a common misconception that they don't. They teach 3,000 characters, which is numerically even more than the 1,800 characters taught in South Korea in school. But as you said, in North Korea you don't even see the very limited usage of Chinese characters in newspapers that you see in South Korea, so it is not much beyond a subject you learn in school. You could say the same about the situation in South Korea, though, since the usage of Chinese characters is really, really limited, mostly to certain newspapers.

The notion that North Koreans say 얼음보숭이 (ŏrumbosung'i) for "ice cream" is a bit of a myth. The authorities in North Korea did indeed introduce this word as a part of a linguistic purification effort, but it doesn't really seem to have caught on. A 1962 North Korean dictionary only has 아이스크림 (aisŭk'ŭrim) "ice cream", just as in South Korea. A 1981 edition of another dictionary and a 1984 encyclopedia introduce 얼음보숭이 (ŏrumbosung'i), but the official dictionary that appeared in 1992 again has 아이스크림 (aisŭk'ŭrim) "ice cream" and not 얼음보숭이 (ŏrumbosung'i). The 1992 dictionary also has 에스키모 (esŭk'imo) "eskimo", which in North Korea is a popular everyday word for "ice cream" which comes from a name of a brand that was popular there.

You have plenty of examples of South Korean language authorities introducing "purified" (often pure Korean) words to replace loanwords, which don't necessarily catch on. For "stapler", the official South Korean dictionary has the pure Korean translation 찍개 (jjikgae), for instance. But I have never seen this term in the wild—instead, people say 스테이플러 (seuteipeulleo) "stapler", or more commonly, 호치키스 (hochikiseu) "Hotchkiss". There is a limit to how much official language policy can dictate actual usage, whether it is in North or South Korea.

Well fancy that-- Everything I knew was a lie!

Would you happen to know anything about the usage of konglish in North Korea then, as in words besides 아이스크림 or 에스키모? Is it more frequent near the border or just as spread through as it is in SK?

Are you talking about loanwords from English in the Korean used in North Korea? Korean was already borrowing words from English decades before the division of the peninsula, as you can see in writings from the Japanese colonial period. So North Korea inherited a lot of these same loanwords. It has nothing to do with South Korean influence, if that's what you're suggesting, as the language communities of the North and South have been effectively cut off from each other since the war.

However, there are often differences in the spelling of such loanwords between the North and the South. So you have 프로그람 (p'ŭrogŭram) in the North but 프로그램 (p'ŭrogŭraem) in the South for "programme", 텔레비죤 (t'ellebijyon) in the North but 텔레비전 (t'ellebijŏn) in the South for "television", and 미싸일 (missail) in the North but 미사일 (misail) in the South for "missile". This is due to the fact that the standardized spelling of loanwords (a problematic and much debated area of Korean orthography) was frequently reformed in South Korea, and probably in the North as well, so the principles of spelling have turned out quite differently between the two. Also, as North Korea uses a lot of loanwords from Russian, even loanwords originally from English tend to be absorbed in the Russian pronunciation, such as 땅크 (ttangk'ŭ) for "tank" or 뜨락또르 (ttŭrakttorŭ) for "tractor" as opposed to SK 탱크 (t'aengk'ŭ) or 트랙터 (t'ŭraekt'ŏ) which is closer to the English pronunciation.

The official language policy in both the North and the South tends to discourage loanwords from English, but it seems a bit more successful in the North, especially when it comes to post-1945 loanwords. If you only focus on the differences between the North and the South, then you see many cases where North Korea uses native Korean words whereas South Korea uses loanwords from English. But you can't extrapolate from that and conclude that North Korea doesn't use loanwords from English at all. This would be a misconception, just like the false notion that North Korea doesn't use Sino-Korean words.

I wasn't implying at all that the North's use of loanwords was due to the South, I was asking how widespread are the English loanwords around the border compared to the far far North. -- Because the South has embraced loanwords much more than the North, would it be not uncommon to possibly hear 찍개 somewhere in the North as opposed to 스테이플러.

Didn't know about the Russian pronunciation thing, is 도꾜/도쿄 also included in that?

Sorry for the late reply as I didn't see this until now.

There is no reason for there to be a difference in English loanword usage in North Korea between the border area and the far far North. Remember, the DMZ is a tightly sealed border and there has been virtually zero cross-border exchange that would influence the language since the Korean War. If we were talking about normal national boundaries with some cross-border linguistic exchange then there would be a gradient of linguistic features taken from the neighbouring state near the border and diminishing as you move away from it, but with the DMZ there is no such thing.

찍개 is a recent South Korean neologism for 'stapler'. There is no reason that North Korea would use the same word. I don't know what they call staplers in North Korea, though.

Once again, the point is that English loanwords were being used in Korean before the division of the peninsula, and afterwards, North and South Korea followed completely separate paths of linguistic evolution. There was no way for people near the border regions to be influenced by what people were speaking on the other side. You might flip the question and ask whether South Koreans near the DMZ are more likely to use pure Korean words due to North Korean influence, and again the answer is no for the same reasons.

도꾜 is the traditionally common spelling for Tokyo that is based on maximum phonetic similarity. In South Korea, the spelling was reformed to 도쿄 to conform to standardized rules about how to write Japanese loanwords, where all non-initial "k" sounds were to be mapped to ㅋ. So this is more of a phonemic spelling. Roughly speaking, "phonetic" refers purely to the sounds, while "phonemic" goes into the more abstract level of grouping the sounds that are considered mere variations of a single sound to the speakers of that language. However, due to widespread resistance, the South Korean reform didn't go all the way in making it phonemically regular—otherwise, we would be writing 토쿄 instead, using ㅌ everywhere for "t" (in concession to the traditional practice, we write ㄷ for initial "t").

This reform took place in the 1980s in South Korea, and didn't affect North Korea, which still writes 도꾜 for Tokyo. It has nothing to do with Russian pronunciation. If we imitated Russian pronunciation, it would come up as something like 또끼오 or even 또끼워.

Place names side, I like that Korean orthography is morpho-phonemic rather than striving for purely phonemic spelling. The same morpheme tends to be spelled the same everywhere it's used, which promotes reuse and actually tends to make writing in bulk easier. It also isolates the written word from shifts in pronunciation over time a little more, something that hangul otherwise runs into problems with anyway.

In practice the orthography is sort of a middle step between the hanja spelling for many morphemes and their pronunciation. Multiple hanja end up mapping to the same hangul block because they're homophones, so there's some information loss, but spelling is morphemic enough that you can recognize the same morpheme in different arrangements. If you can guess what hanja it might be though you can often understand a word more deeply.