"Hur går det" isn't often used in the "how are you" sense, I'd say. It's often used to refer to something specific:
"Jag har väntat i en timme. Hur går det?!" => "I've been waiting for an hour. How's it going?!"
"Du har använt Duolingo ett tag nu. Hur går det med svenskan?" => "You've been using Duolingo for a while now. How's it going with the Swedish?"
"Hur går det till?" => "How does it work?"
Could "how is it walking" be correct? Or is går only 'walk' as in 'go' (ie german gehen)
Whilst literally correct they don't want us to translate directly for sentences like this which are more likely to be used in the colloquial form "how's it going?" rather than asking about how something can walk (e.g. a robot or something that you'd expect not to be able to walk). I'm told that "hur går den?" is more appropriate in that situation
I'm not so sure it's archaic. Not frequently encountered, certainly.
Plus, it's the translation, clearly.
From, How goes it? it's very easy to understand this phrase as the commonly expressed, How is it going? No?
But I think, from the start, there's been an emphasis that Swedish verbs do not have this option of -ing forms.