How about common usage? Usage represents standard grammatical expression.
I am not following you. What is a “metaphorical element” as opposed to a “metaphorical utterance?” I. A. Richards in literary rhetoric explains elements of a metaphor as “tenor” and “vehicle.” McLuhan uses “ground” and “figure.” You do not explain how you use the phrase.
What is the diffierence between “utterance” and speaking? Would not speaking be a better term? I think you need to define your terms as you go along because of the multiple meaning of specified terms in various disciplines. Otherwise you will confuse your audience.
Who? What are your sources?
What question? How does it become more difficult? How do you mean “difficult”? What was the difficulty with the writer? The reader? For example, how do you apply this difficulty to the metaphorical language in the Psalms and Proverbs? David and other psalmists were quite conversant in figure of speech, which informs us that metaphor has been part of standard speech for a very long time, indicating that authors then understood the difference between the literal and figure of speech. Where was their difficulty?
Actually, that is not the case. Dictionaries record what already exists in common dialects. The dictionary authors simply describe what already exists in the language prior to publication in the dictionary.
But language continues to change and evolve. Meanings only coincide because speakers share common grammar, syntax, and words. There is dissonance with new cultures or the attempt to disrupt cultures through force and attempts to change a language (i.e. Ebonics and critical theory)
How? Linguistics is the study of language in all its forms. Speaking is a form as is writing. So, I am not sure what you are saying. You never expand.
I am not sure I agree with you on this point. Metaphor is an extrapolation from the literal meaning of a word. If there was no literal meaning, then a metaphor could not be expressed for forming a picture in the audience’s mind (i.e., “He chaired the meeting.” Chair in this sense is a metaphor, but it rests on the literal chair for its meaning).
I do agree with your conclusion about author intent, but the way you got to it was by winding through digression.