weit links/rechts stehend/orientiert (?)

For the English I would toss 'far-right' and 'far-left' into the discussion, which might correspond to maxx's #2.

>>das "Stramme" assoziiert man ja gemeinhin eher mit rechtem Gedankengut und militaristischem Gehabe

Yes, and I would say the same is true for the English. Perhaps because hard-right politicians really are hard in the sense of tough, hawkish on defense and military policy, 'hard-right' sounds more idiomatic to me than 'hard-left,' which I notice you don't cite examples for. Perhaps the same is true of 'stramm,' which makes me think of a stiff, upright military posture, snapping to attention.

Maybe there's also a difference in the modern day that wasn't there in the 20th century, because today far-left political parties in developed nations tend to be pacifist (and thus not 'hard' in the sense of military force), while in authoritarian nations, one-party states ruled by corrupt elites, 'left' doesn't really have much meaning any more, it's only 'hard' and little else.

And '-extrem' is indeed more extreme than just 'far-.' I'm sure there are discussions on 'rechtsextrem' etc. in the archive, but I would be inclined to use 'ultra-right-wing' in English, or else the noun 'extremists': 'right-wing extremists,' 'left-wing extremists,' implying those willing to use violence to further their ends.

But that's only my own hazy sense of the terms -- see if others have another perspective.

"Nur die Ultralinken waren wieder einmal nicht einverstanden." (Leserbrief in BZ)

Im Deutschen finden diese Worte sowohl als Adjektive wie als Substantive Verwendung und sind recht gebräuchlich.

LInksaußen assoziiere ich mit Fußball, ehrlich gesagt. In einer politischen Debatte habe ich das Wort noch niemals gehört, ebenso wenig wie Rechtsaußen. Aber von Fußball verstehe ich nix. (=nichts). Aber ich denke, in einem Lexikon geht es nicht um Assoziationen, die sind etwas Persönliches. Allenfalls um die Konnotation eines Wortes.