Best of all, it's not much used, as paths go (8)
I believe the answer is:
unbeaten
'paths go' is the definition.
Both the definition and answer are adjectives. Perhaps there's a link between them I don't understand?
'best of all it's not much' is the wordplay.
I cannot quite understand how this works, but
'best' could be 'beat' (I've seen this in another clue) and 'beat' is located in the answer.
'not' could be 'un' (prefix meaning 'not') and 'un' is found in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is located in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'used as' is the link.
Can you help me to learn more?
(Other definitions for unbeaten that I've seen before include "Yet to lose" , "Not yet defeated" , "Undefeated" , "Not defeated or vanquished" , "Never defeated" .)