I just downloaded and ran the Linux version of Sublime Text 2. All German characters as well as all dead keys on my keyboard are ignored. Nothing happens when I press those keys. So I can't type the text I need to type. This is a text editor that you can't write actual text with. Am I right? What use is that? No other programs in my computer have problems with those characters.

"The point is that you quickly come up with short forms of long words, in whatever language, so that in itself is a poor argument against switching to metric."

Yes, that is true. In Swedish and German "kilo/Kilo" is used for "kilogram", but "kilometer" is always in the full form in Swedish. In Korea they mostly use "kilo" for "kilometer", but they use it for "kilogram" as well! I guess context helps al lot.

"in casual speech, people in metric countries say "k" for kilometres"

We do???

I've lived most of my life in metric Sweden, and for years in Germany and in Korea (both metric). I've never ever heard anything like "k" for "kilometers", except for the abbreviation "kmh" - "ka em ha" - that the Germans often use in speech, but I've never heard any German use "5 k" for "5 Kilometer".