Well, we've kind of already seen that. At least, in a few cases.
Like the Inanimate Zoan Users, like Lassoo the Dog-Gun and Funkfreed the Elephant-Sword. These are just purely the "Devil" controlling a object that has "eaten" a Devil Fruit, with no other will involved.
https://onepiece.fandom.com/wiki/Category:Inanimate_Zoan_Users
And the "Unsuccessfully" Awakened Zoan Users, like the Jailer Beasts. Where the "Devil" takes over the Human host's body completely.
https://onepiece.fandom.com/wiki/Jailer_Beasts
And, in fact, the Gorosei themselves mention that "All Zoan Fruits have a will of their own". (Chapter 1044)
So, at the very least, Zoan Fruits have wills of their own. This much is just canon.
I, personally, think it's pretty likely that ALL the Devil Fruits have some wills of their own. Simply by the nature of them being the dreams and desires of the people who "wished" them into existence. All the Fruits want to see their "Dreams" come true. They want to make their "futures" into reality.
(Chapter 1069)
There isn't that much evidence that the other Fruits have wills of their own. But, I feel like it's pretty probable. At least on some level. Zoans could still be the type of Fruit with the most will, though.
As for Imu being a "Rogue Devil Fruit"? Well...it's not impossible. But, I don't see a lot of evidence for it, yet. Imu hasn't really acted like they want to "free" the Devils from their Fruit "prisons" or anything. In fact, with Imu letting the God's Knights use Devil Fruits, it seems like Imu doesn't really care about Devil Fruits any moreso than anyone else does.
Imu DOES hang out in the Butterfly Garden a lot. Which...yeah, I guess that would be what a sentient "plant" would do? But, other than that, I don't really remember anything that really points to Imu being a "Rogue Devil Fruit" that took over their host.
It could happen. But, I don't personally think that's the way Oda's going with it.