Yes there is nothing explicit in that verse to identify the rider of the horse as Jesus with the exception of the white horse. (Later in Revelation Jesus is specifically mentioned as riding on a white horse.)
The part of revelation dealing with the four horsemen says they are give authority over the four parts of the earth to kill a fourth of mankind in four ways
famine
disease
civil war
wild beasts
So maybe literal wild beasts or more likely some governmental entity.
Crowns simply denote rulership. The rider of the white horse does not have the diadamos kingly crown of Jesus but rather the laurel military crown. Other unholy entities in Revelation are also depicted with crowns such as the Dragon and the locust/scorpions that come from the Abyss.