One demands former thespian (7)
I believe the answer is:
exactor
'one demands' is the definition.
(exactor = person who makes unreasonable demands)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for exactor that I've seen before include "One forcing payment" , "Individual demanding" , "demanding type" , "Extortioner" , "One demanding and obtaining (something from someone)" .)