Awfully convenient that the etc. happened to be in brackets then. I guess the previous sentence ends at the etc. when I don't put it in quotes and after then if I do.
But you should always use "i.e." because it's an abbreviation for two words. And I can't even think of a case that you wouldn't follow it with a comma (i.e., "i.e.,"), so that doesn't conflict with the ". " end-of-sentence pattern.
