If you're only targeting modern browsers (latest Chrome/FF/Opera/Safari, IE10), is this still true? I was under the impression the recent browsers were standards-compliant enough that you could use vanilla JS.
Of course, most developers still have to target older browsers, but for a private Web app where you know your target audience, this shouldn't be a huge issue.
What about making PadMapper client-side, including the Craigslist scraping? It'd have to be done on each request, which would hurt performance, but it may be a way of staying within their TOS (not sure if they have a provision against that; I don't use craigslist so haven't read their TOS).
One of the screenshots in the blog post shows an ad with a title saying "Meeting Burner" (with a space) with a "MeetingBurner" (no space) keyword. It isn't dynamic keyword insertion; it was an ad they wrote specifically for this keyword.
Of course, most developers still have to target older browsers, but for a private Web app where you know your target audience, this shouldn't be a huge issue.