Lacking balance, and nasty due to change (8)
I believe the answer is:
unsteady
'lacking balance' is the definition.
'nasty due to change' is the wordplay.
'to change' is an anagram indicator.
'nasty'+'due'='nastydue'
'nastydue' with letters rearranged gives 'UNSTEADY'.
'and' acts as a link.
(Other definitions for unsteady that I've seen before include "Not even" , "Wobbly" , "likely to wobble" , "Rocky" , "Wavering" .)