Thanks for the comments and thought you’ve all put into the article!
To hopefully clarify, the point my lawyer makes about signatures holding up is that they are rarely used to determine the validity of a contract—whether written or electronic. Neither type comes with a guarantee, and proof usually relies on actions that imply “acceptance” and are easier to verify than signature validity. In this regard, an e-mail or even a nod of the head can be used for contract acceptance. The article focuses more on using PHP, HTML and PDF specifically to create professional, quick, free, and universally accessible means of entering agreements, receiving confirmation, and providing receipts.
With client impressions and experience in mind, my pudding hopefully retains a balanced ratio of egg. :)