My freekick taker who scores 3 out of every 5 freekicks is less than 70% creativity, but he has over 300% shooting and finishing and about 250% strength.
I don't think creativity matters for freekicks. When I asked support a question about special abilities they confirmed to me that the freekick SA boosts the shooting finishing and strength of the player by about 50% so those are the attributes essential for freekicks