This person, bad, holding firm up? Neither bad nor good (8)
I believe the answer is:
mediocre
'neither bad nor good' is the definition.
'this person bad holding firm up?' is the wordplay.
'this person' becomes 'me' (I've seen this in other clues).
'bad' becomes 'dire' (**).
'holding' is an insertion indicator.
'firm' becomes 'co' (a firm is a company).
'up?' is a reversal indicator (in down clue: letters go upwards).
'co' back-to-front is 'oc'.
'dire' going around 'oc' is 'diocre'.
'me'+'diocre'='MEDIOCRE'
(Other definitions for mediocre that I've seen before include "Rather poor" , "Rather inferior" , "Fair, middle of the road" , "Somewhat inferior" , "Not very good" .)