"Also, the Roman Republic were prolific slavers too. I say this because you speak of the Empire and slavery but then go into a "But the Republic..""

My point here was about freedom of thought. And that seems to have been way more valued in the republic, than in the empire. (In general, good and bad are relative terms to me)

"The demand for reform that would eventually motivate mass conversions to Christianity was already well established before Caesar was even born."

And maybe so. But christianity in general was not really about freeing slaves, either.