Skan, I understand your intent and I don't think your intention is to create a caricature, but your premise leads there.
Or does the logic of your system lead there?
The Calvinist preacher should take great care that he doesn't seek to be "interesting" at the expense of the Gospel. It's not about the man, it's about God's glory.
But as long as he doesn't water down or neglect the gospel why would he seek in any way to be interesting? Wouldn't that only undermine the Calvinistic premise? That is my question here.
Let ask a question in return. Since the preacher is handling God's holy word, should he not desire to proclaim it well? The preacher is a herald of a heavenly message. How he executes his duty says a lot about his love for God.
But what does "proclaim it well" mean in a system where persuasiveness, interest, and appeal have no effect? Any level of emotive appeal, interest, excitement, persuasive intent would appear to undermine the premise that only a supernatural predetermined work of the Holy Spirit will change their hearts.
In fact, in your system, the more boring and uninteresting the preacher is the more obvious that God worked if someone where to come to faith, right?
Another thing, what of the Arminian preacher? Does he actually believe the manner in which he preaches improves the Gospel message? If so, then he denies Romans 1:16.
How so? We believe the gospel is an APPEAL to be reconciled, so to make it as APPEALING as possible is consistent with what we believe it is intended to do. The gospel enables an enemy of God to respond and be reconciled in our system, but in your system it only informs the pre-reconciled of their reconciliation...you don't appear to leave any room for an appeal.
In short, God will call His elect no matter how much, or how little, passion is displayed by the preacher. It is the Gospel that is power of God unto salvation (Romans 1:16).
That is my point. So, it only reasons to suggest that you leave the passion/excitement/appeal out so as not to take away any glory from the effectual working of regeneration done by the Holy Spirit. Your preaching classes should be much different than ours.
Preaching the Gospel well glorifies God, and is there any downside to that?
Again, you need to define 'well' from your system's perspective, because from my understanding 'well' means accurate, not interesting.