speech is not composed of words
it is composed of verbs, nouns, adjectives, subjects, articles, etc.
We agree that speech is composed of words, then.
While I can agree that having such a system for a new writer would handicap him, it would only benefit experienced writers such as myself. As for machine manipulation, that's part of the point. A character stream is difficult to manipulate in comparison; this idea could form the basis of a very complex and efficient text manipulation system. I don't like 4chan's /r9k/, but imagine an /r9k/ that can't be trivially bypassed by creating invalid strings of text. The very purpose is to add structure and enable greater things.