I'm not sure I agree with your analysis, because I would say that, even if the pronoun "I" is implicit in the second part of the sentence, it's still an independent clause: "(I) still do so to this day" is a completely formed proposition. But I studied English as a second language, so my grammar might be completely off.It has nothing to do with pauses. It has to do with the fact that "still do so to this day" is not an independent clause and cannot stand on its own.
If you had said, "and I still do so to this day," the comma would be fine because "I still do so to this day" is an independent clause.
As for commas and pauses, I was wondering if it was something of a difference between Italian and English, because I was taught that, while a comma might indicate a pause in reading, they are used primarily to separate different clauses in a sentence. Using a comma every time you would take a breath in reading the text aloud would result in broken sentences and ambiguous meaning. Reading a text in your head is not the same of reading a speech aloud, which has it's own rules and symbols to read it clearly, correctly and effectively.