Surely cicero was capable of speaking demotic, and writing Katharevousa?

The implication that Shakspear spoke in meter feels false. Poets rhyme for amusement, but can also just "say" pass the salt and mean it non-ironically.

You can ask for the nearest coffee shop in Latin without using ciceronian style, and its good latin. Spending the mental energy to think it may be going beyond the pale.