No, Donald Trump is not a bully.
My guess is Trump gleaned much of his body language from the construction trades. He swaggers and talks very much like an iron worker bull steward. He refers to "his people" as does any union steward worth his salt.
Disagreements between a steward and a superintendent can get heated but a jurisdictional dispute between two stewards, each representing a different craft, with a contingent of each craft looking on is high drama. They would do Leo Durocher proud. Hard hats are slammed to the ground, dirt is kicked in the air and statements may be punctuated by belly bumping just to make sure the point is well taken. An outsider stumbling upon such a demonstration of rage would probably reason incorrectly that the antagonists were mortal enemies but while they may not care for each other much they have probably known one another for years and respect the others position if not his person.
Trump speaks the way people who get their hands dirty talk to each other everyday. Small wonder he is so popular with the working class.