An interesting take. I know Dante would agree with you as Brutus and Cassius live out eternity it the depths of the Inferno. Lucan I'm sure disagrees and I suspect Ovid does too. But the former was suicided by Nero and the later banished by Augustus.
I'm quite curious about Dante's hero Virgil, he seems more a fan of the Republic than the empire, but I have not read him in a long while.
Rome as an empire began with the conquest of Ostia.
imho, calling pre-Caesar Roman gov't a republic shouldn't be taken seriously. It was run by leaders of well-to-do households belonging to about 35 families, and they served in the senate when it suited them, not due to any elections or pesky stuff like that.
The supposed end of the so-called republic really just marked the evolved addition of an obviously necessary fulltime permanent chief executive. The emperors received consulships and generally chose their own colleague (consuls were two at a time). Claudius (formally emperor #4) revived the lapsed office of Censor and filled it with himself.
I couldn’t find the one I remember, showing Satan forever gnawing Judas, Brutus, and Cassius.
https://commons.wikimedia.org/wiki/Category:Lucifer_devouring_Cassius,_Brutus_and_Judas