"Formal" is in the mind of the reader... While it's the job of a good writer to covey his or her meaning to the reader, there's really no foolproof way of doing so, and that is especially true in the internet age, where things you write are being read around the world, by a host of different cultures. To my mind, your version (using proper modern grammar) was the more formal, while my version (using a more archaic manner of speech... "I then" is so rarely used anymore) sounded more playful to my ear.

As for "iambic tetrameter" and so forth, I stand in awe of your linguistic prowess. I can see why Perl appeals to you, being a programming language designed by a linguist. Thanks for sharing your story of "MS Word user to poetical programmer" :-)