If you find yourself stuck, create a new character and just do the 1 and 2 * Be More Objective challenges. Both are capable of being completed in the first go with no frustration, hair pulling, or controller throwing. Hope this helps.
Be More Objective 2 Star friggin' pisses me off. The enemy bots only focus on me, it feels like, and they really, really, REALLY INFURIATE ME.
I really want the Speed Slings. But I just can't frikkin' do it. I'll get to the Operative objective (with some difficulty) and then I'll just get completely shut out. Their Engineers kill my hackbox while I'm hacking, and my bots seem to refuse to kill them, so in the time it takes for me to switch from the PDA to the weapon and fill them with bullets, they will have destroyed the hackbox AND their team (which consists of several Heavies when I'm using a new character that as only done the first star version of the same challenge, mind you, so I call [censored] on that anyway) will promptly mow my ass down.
More than a little frustrating. I'd appreciate any advice, but I've looked up several walkthroughs and well, the Operative challenge is as far as I can get regardless of tactics.