Keyboard shortcuts in Mavericks when using international keyboard layouts
I'm going to assume that you're running your Mac with a Norwegian localization, and that you're probably using a Norwegian input keyboard (one of three available), but that you might be switching to an English language input keyboard on occasion. Your language localization, input language keyboard, and VoiceOver voice language are all different parts of your language setup. Even though I switch input language keyboards and voices, I use a U.S. English localization on my account. Some users create alternate user accounts for themselves in a different language localization (e.g. English and French), and actually switch between accounts.
First question: does Control-F4 work for you to switch between your TextEdit windows? The Apple Knowledge Base document on OS X Keyboard shortcuts:
lists Control-F4 as "Move focus to the active (or next) window" with Shift-Control-F4 as "Move focus to the previously active window". I'd expect these Control+F-key shortcuts to work for all Macs, regardless of localization.
Secondly, it's not necessarily true that the Mac kyeboard shortcuts for your localization will be the same as for someone using an English localization. I came across a Google search reference that mentioned that for one user of the Finnish keyboard, for example, the shortcut Command+< (where the last character is the "less than" symbol) worked to switch between windows of an application. This was back in 2011, so I don't know whether this is still true. And by the way, I just checked all three of the Norwegian keyboards for the Mac (Norwegian, Norwegian Extended, and Norwegian Sami-PC), and on all of these keyboards the key to the left of the "1" key is reported as "<" (the less than symbol). One of the first things you need to determine is whether the default keyboard shortcuts for your Mac are actually the same as the ones for someone with an English language localization. To find out what the default shortcuts are for your Mac and its language localization, go to "System Preferences". I'm not running Mavericks, but I've read that the "Language & Text" option where your localization is set has been reorganized as "Language & Region", where you set your preferred languages. However, the place you really want to check is "Keyboard" under the "Keyboard Shortcuts" tab that is named "Shortcuts" under Mavericks. This is where you can customize and change the keyboard shortcuts for various actions, but where you can also check what the default assignments are. In the case of switching between TextEdit windows, I would navigate to the "Shortcuts Category" table and interact, then select "Keyboard & Text Input". VO-J to jump to the associated "Table of Shortcuts" and find "Move focus to next window". I'll hear the default keyboard shortcut for this announced as Command-accent, where "accent" is the grave accent on the key to the left of the "1" key in the numbers row on my Mac. Apparently, this was the way the Finnish user found out that the Command+< shortcut was the default shortcut for switching between application windows. I don't know whether this is still true, or what you will find when you check the default keyboard shortcuts for Norwegian
Some problems (like whether Command+Right Arrow or Left Arrow) works for your browser, may be specific to your language localization. (By that I mean there can be a bug in how this works only for your language. A few years ago there was a bug in VoiceOver focus on iTunes syncing with the iPad Nano, such that in the German localization you couldn't read the playlists, podcasts, or contacts on the tabs when the device was connected. The workaround was to force iTunes to run under an English localization when the user wanted to change selection of playlists, podcasts, etc. but to let him sync the device with iTunes launced in German, in the usual way until the problem got fixed.) If Command+Right or Left Arrow works for you when VoiceOver is disabled, then you can try first issuing the VoiceOver escape shortcut (VO-tab, or Control-Option tab) before pressing Command-Right or Left arrow. VO-tab instructs VoiceOver to ignore the next command. An example where this was recently discussed on the mac-access list was the keyboard shortcut for starting a new audio recording in QuickTime. The QuickTime file menu lists this shortcut as Command-Control-Option-N, but if you issue this with VoiceOver active you just hear a "boink" sound, because the shortcut conflicts with the VoiceOver shortcut for finding the next auto web spot. However, to avoid having to navigate to the File menu to start a new audio recording, VoiceOver users can press VO-tab followed by ommand-Control-Option-N. That trick might work for your Command-Left Arrow and Right Arrow web navigation, too. Another thing you could try is downloading the WebKit nightly build to use in place of Safari. WebKit is the engine that underlies Safari and a number of other browsers. The nightly builds incorporate changes that are being worked on since the last full Safari release, so sometimes they can contain fixes for ongoing problems. Becasue these are not official releases, they can also contain new bugs introduced as people work on things. My guess would be that your problem is language localization dependent, however, and not likely to be fixed by using the latest WebKit version in place of Safari.
For some keyboard shortcuts that are difficult to type, you can try using VO-h-h to bring up the VoiceOver commands menu. This was the typical way that VoiceOver users with keyboards where it was difficult to type the "sort" command (VO-Shift-backslash on an English language keyboard) would access the "sort" function. In other cases, such as toggling disclosure triangles, Apple chaged things so that pressing right or left arrow keys would work in place of the other keyboard shortcut.
It's actually not a good idea to tie keyboard shortcuts to the specific location of keys on the Apple Keyboards -- for one thing, it would mean that you wouldn't be able to use any other third party keyboard. If you really want to remap your keys, I'm sure that you can do this with KeyRemap4MacBook. You might even contact the developer with your questions. That's how Eric Caron got the solution of mapping the VoiceOver keys to Caps Lock.
Finally, you're not likely to get a good discussion of international keyboard problems on the AppleVis site, since this type of discussion is more likely to occur on the mailing lists. The only discussion of these issues I've seen on this site are the occasional complaints and questions. I think there are a few proficient Mac VoiceOver users from Norway on the macvisionaries list -- John André of A-Pro Studio (a musician) always struck me as being a sensible fellow when he posted. And we've had other language related discussions on the mac-access list.