I apologise for not having the time to respond to your entire post. For now since I read the article about the variable release threshold, and I keep the threshold down, it results in subconscious fluent speech: somehow there is no "block" and the anticipation disappears into thin air the moment my speech plan changes into articulation. So my experience is a confirmation of the variable release hypothesis. In addition it seems that my fear of a motor execution problem is unwanted, as the motor execution goes just fine. I am now making flight hours in my work as a doctor and I hope that the anticipation will decrease in time.