I think Orcs are definitely driven, though not only by fear. They're also filled with hate and bloodlust by Morgoth.
Also... maybe the Balrogs are cowards, like Morgoth, despite being terribly dangerous and powerful. I don't know whether that would be at all consistent with how they've been depicted so far, though.
Also, I'll back off of saying Gothmog should not start the Dagor Aglareb, if it's important for him to do
something significant and we can't work in any other action for him this season.
Honestly I don't have a problem, necessarily, with Petty-Dwarves attacking Elves for no reason and getting killed in reaction, since they behave that way in War of the Jewels. However, this wouldn't fit well into our timeline without changing it. I made a
comparison of the canonical story (Sindar fighting the Petty-Dwarves) and the proposed story (Feanorians fighting the Petty-Dwarves) to show how where the logic holes come up, because of how the situations differ.
The biggest problem, to my mind, is how the Feanorians then relate to the Blue Mountains Dwarves. In the canon story, the Sindar mistake the Petty-Dwarves for vicious animals, but have no trouble telling the Blue Mts. Dwarves are people since they operate openly, so they don't attack them. However, if the Noldor mistake the Petty-Dwarves for Orcs instead, they'd realize the Blue Mts. Dwarves are the
same kind of Orcs, and surely would attack them.
I apologize that this is tiny and hard to read.
Edit: If the logic holes of this story can be overcome in a satisfying way, without anyone acting out of character, then my objections would be overcome.