Love ya brother, (especally DUFU) but here is the flaw in Lutheran and reformed covenant theology. If we claim sola scriptura and then go to some historic confession or creed we are no longer sola scriptura. For reformed to refer to the WCF (for example) puts them in the same boat so to speak as the catholics when they go to the traditions of the church. I know there are well reasoned rebuttles to this statement, but on this topic, Here I Stand.
You have I think, in a couple of sentences, confirmed everything which the author of the article is arguing.
Yes, there are. Particularly if the creed or confession is a summary of what the Scriptures teach. Read the Apostles', Nicene, or Athanasian Creed, or the Lutheran Confessions, for that matter, and show me where they depart from Scripture.
Every church, every Christian, has a creed or confession, whether written or unwritten. Some just won't admit it.