Thanks for this! I had played with some of the other plugins that add shortcodes for ALL the Foundation features, but I just wanted the grid. Works very well once you get used to what it does.
Would it be possible to detect non shortcode-wrapped content during your filtering and wrap those chunks in a row container for correct padding?
Something also seems to be happening for me if the first paragraph is on the first line in the editor - it doesn't get the autop but subsequent paragraphs do.