I will work on those. The problem is not the diagrams, but my lack of skill in diagramming with a mouse.
The words "copula" and "copulative verbs", incidentally, are unfamiliar to Americans. We call them "linking verbs". I am guessing that in teaching students, "copulative" was too close to "copulation" to keep their attention.
Similarly we usually refer to auxiliary verbs as "helping verbs".
Back to your sentences, I would treat all of the simple predicates as linking verbs.
Student or Learner