I'm with you almost all the way to the end. Either way, I think you got it mostly right (note: I clearly don't know shit except for what everyone else saw).
I was under the impression that Tyrell was the one responsible for spreading the attack to the 71 buildings. The little meeting with Tyrell, Angela, and Mr. Robot showed where all the paper records went. When Tyrell said he could still do it, I was lost. Then when it still happened, it seemed to me like he was the one who said "fuck it, take 'em all out." His "turn" at the end, I assumed was part of the instructions. Tyrell had been under suspicion, which the Dark Army knows. If he's seen as a victim that changes the framework the FBI is working from-- so the handcuffs, the fire, and him yelling what he was yelling when he got caught.

I definitely think that the last two episodes were to keep Eliot, who had become a known liability, busy while the real shit went down.