Yeah I think Akainu will be fine with Imu’s existence, his hatred for pirates trumps all and his twisted tortured mind will give him all the excuses to hunt down Luffy. Nevertheless bending the knee literally to this demon is out of character, his ideology aligns with the WG, or so he thinks, so he has no problem enforcing their agenda while he does his job the way he wants. At his heart he’s not a demon, he’s doing this because he thinks it’s better for the world.
The Gorosei in turn are just some crooked demons with no self worth, only dedicating their lives to Imu