Interesting thread. I will have to read it fully to get a fuller understanding of the discussion in here, but I'll give my answer to the OP and the addendum.
Occasionally I utilize some interrogation tactics. Hostile questioning.
I see the use of psychological force falling on a continuum of hostile and less hostile methods. I am careful in having methods to fill every spot in that continuum, so that I may not need to resort to an needlessly forceful method where a softer method is applicable.
Some tasks require authority. People are funny figures in needing such authority and how they respond to it. Again with the continuum of expressing authority. Too much of it is silly, some of it is required to get some job done. Most tasks I do I accomplish with displaying no authority whatsoever.
I dont want to be a dick and I'm not enjoying if I were, but I'm ready to use psychological power to some pre-determined level, determined by assessment of the situation. Some situations call for a mild plead. Some for mild persuasion. If I acted in a situation where someone's life and health were in immediate danger, I would allow for harsher words.
I sometimes do some kind of development work, project leading, designing and such. I know that they have rarely the chance to injure people severly, but knowing how a project is managed effectively, I can spot some important parts in the design process that have to be done well. I'm not interested of forcing everyone to do anything my way, but instead I know there's a relatively large collection of valid approaches to some situation. I would not try to stop someone from using a method that isn't a danger to our objectives. If I were in doubt, I would politely ask until I got the picture of the situation. Again, if I had some superior method in place and I thought its worth the trouble to press on the issue, I would offer some arguments to using my method. I would assess if trying to convince someone is worth the trouble. I might also deduce that I don't have sufficient knowledge of the problem in question, and leave someone wiser or more experienced to handle the issue. But yeah, I would be ready to defend my viewpoint if necessary.
If I noticed I've started bullying someone, I'd change my behavior until it's no longer bullying.