"Not the best illustration" isn't equivalent to "poor choice." Caesar isn't a bad example, per se, just not the best one. I'm simply saying (re: "A large part of rhetoric, for example, is breaking grammar for effect") that an example from a language where no grammatical rule has been broken isn't the most apropos. You may have given the sentence in English, but everyone knows its provenance.

Here's one from English, in honor of the upcoming holiday:

Go back to Mississippi, go back to Alabama, go back to Georgia, go back to Louisiana, go back to the slums and ghettos of our northern cities, knowing that somehow this situation can and will be changed.

As far as your claims, (2) is contentious. Some grammars rail against the evils of the comma splice, others acknowledge its place and provide more nuanced guidelines for proper use. It's never been a cut-and-dried issue. I personally disagree with (1) for English while agreeing with it for Latin, but that is neither here nor there.

Thanks for your feedback. I think I now understand your argument and, while I have a hard time believing the claims upon which it rests, I believe that reasonable people could believe them.