Ah, I know this band. Not a bad band at that.
But as far as "avoiding politics" goes, you're never going to avoid politics with history, especially with recent history. Symbols and imagery instinctively give the impression - as Yahko seems to have - of the band being more than what they might actually be. It's something you cannot avoid, as much as you may want to avoid it and as much as you might personally will it to not be the case. It is VERY important, though, that we are aware of our own perspectives and our own impressions and that we can recognize that by giving into those perspectives we may be making judgments based on false pretense. Ideally we should not judge books by their covers, however, it should be fairly obvious to Toroidh and others that they will be judged as such. It's one thing to be ignorant and have no idea and another to be well aware of the connotations of your imagery and style and know what they signify to others. I don't imagine Nordvargr to be ignorant.
That all said and done, I wrote recently among staff about a similar issue that came up with lyrical content. It's my own (certainly arguable) perspective on this issue, but one which - maybe - could shed light on this topic. With imagery it's a tad more complicated, but the same thoughts still stand:
There is a difference between lyrics that espouse Nazi ideology, lyrics that build off of the same sources of Nazi ideology, and lyrics that refer to the Nazis as a historical phenomenon. Some of you may scoff at this, but this is an important point (especially because of what I will say in the section below). The themes of your lyrics are not necessarily "National Socialist" if you're simply talking about what the Nazis did or believed in. Those lyrics are not necessarily "National Socialist" if you're referring to the same sources that the Nazis used, such as Germanic paganism and white supremacy (both of which are often lyrical themes on their own accord). Lyrics are "National Socialist," however, if the creed of "National Socialism" is embraced and adopted and pushed as an agenda. You can truly say at this point that the intentions of the author are to convey "National Socialist" themes. These differences are not mutually exclusive, but it helps to understand that not everything that people so easily associate with "National Socialism," such as paganism, racism, anti-semitism, fascism, and so on, automatically means that the intent is to prescribe "National Socialist" ideology. You can be a racist pagan fascist Jew-hating asshole and also not a "Nazi."
Next, because metalheads (and people in general) so much enjoy using "National Socialist" as a slur to degrade others, throwing that term around has become ubiquitous to labeling everyone who may or may not have any minor aspect of their music linked to the sources of Nazi ideology or even to World War Two itself as "Nazis" or "Nazi sympathizers." Sometimes it's as innocuous as a band singing about military history or about their ethnic heritage being labeled as "National Socialist" because they talk about the Germans in the war or refer to their heritage as Germanic. In other cases even the use of terminology associated with the Nazis is enough to warrant that label, even if that use may be satirical and not sincere. When we so easily fall victim to doing the same thing, it becomes equivalent to fundamentalist Christians declaring everything opposed to their values as "satanic" without trying to understand if that's actually the case or not. Yes, there's lots of horrible people out there, however, that does not mean they are all Nazis.