Katzner's Russian-English dictionary freely translates никода as "never" or "ever" when translating into good idiomatic English. The same for Ничего ("nothing" or "anything"). You don't really have to consider either a double-negative - just don't translate either in the positive sense without не as part of the process.
I noticed that the computer-generated pronunciation of double consonants in Russian is, shall we say, lacking. The key to pronouncing any double consonants is Russian is to follow the first sound by a short pause and then pronounce it again. Practice it with a distinct pause and then try shortening it as much as you can while still keeping the sound distinct from that of a single consonant. With DL's pronunciation, I cannot actually distinguish double consonants from the single ones.
That is how the Italians and the Japanese pronounce their doubled consonants. For example, "pizza" in Italian is "piz-za" (https://translate.google.com/#it/ru/pizza) and "konnichiwa" in Japanese is "kon-ni-chi-wa" (http://forvo.com/word/konnichiwa/#ja).
(It is also apparently how to pronounce doubled consonants in Elvish. ^_^ Recall when Gandalf says the Elvish word for "friend" in The Lord of the Rings - https://www.youtube.com/watch?v=DgHCM68KkPY)
Really? I hear the double "н" here clearly: http://forvo.com/word/%D0%B0%D0%BD%D0%BD%D0%B0/#ru (in all three recordings). That said, the double "н" is not always pronounced that way (now that I thought about it). It is commonly found in many Russian passive participles: сказанный (said), сделанный (made) etc. where the pronunciation of the double "н" is much less articulated (even though I can still clearly hear it e.g. here: http://forvo.com/word/%D1%81%D0%B4%D0%B5%D0%BB%D0%B0%D0%BD%D0%BD%D1%8B%D0%B9/#ru )
What would the Finnish way of pronouncing double consonants?
I think I sort of hear it in the first example, but the others sound like just one long n. Here's the first word I could find with double n http://forvo.com/word/k%C3%A4nnyk%C3%B6ill%C3%A4/ (with/by mobile phones). Here's short n for comparison http://forvo.com/word/munissa/
Here's double k http://forvo.com/word/rakkaisiin/ Which is essentially just longer silence than in short k (which you can hear in kännyköillä). And here's double l http://forvo.com/word/illalle/ again just longer version of l http://forvo.com/word/kalotti/ .
It's interesting to know what you hear in these! After all it's not just about what is being said. It's also what we assume is being said. One "fun" fact is that even though Finnish has strict categories for long and short phonemes, the the longest short phonemes are actually longer than the shortest long ones :D Finns aren't aware of it! They think they hear something that doesn't actually exist :D I have no idea how foreigners are able to learn this! And actually, many don't.
They are not even close.
Ссориться = to quarrel;
спорить = to argue (as in "to argue with somebody" or "to argue about somethig", not "to argue a point" - that would be "аргументировать");
обсуждать = to discuss (no animosity is implied).
"Дискутировать" is used, but not commonly. It means something like "to have a prolonged discussion".