The Dust Men are a gang/cult of personality, and so are the First Sons. The Reapers, however, are all either drug dealers or ordinary, mind-controlled citizens. And you slaughter them by the dozen.
Only if you're evil. If you're good you have the option of chaining them down and letting them live. You are far more likely to kill them lots either way though, since you don't take negative karma for killing bad guys. Sucker Punch might have netted some fridge brilliance on that point if you got more infamous for killing Reapers...
Karma represents your reputation among the population. How they hail you as either hero or villain is judged by them, which depends on your actions. You could say that you don't get bad karma for killing them because the population doesn't know they're normal humans, but then Fridge Logic is invoked when some of Cole's actions that net him good/bad karma aren't even seen by people.
The Dust Men are a gang made up entirely of the Warren's homeless and destitute who were united under Alden with teh promise of a better life. Think about that for a second...
Though they lost all their sympathy when they took their armored buses and started machinegunning every single person in the city. But that's a fridge horror all by itself. How many people did they kill?
Evil Cole: Because of me, Empire City is a wasteland. I've taken this place down notch by notch, and it's never getting up again. Kessler thought he was preparing me to face some "Beast", that I'd be using my powers for the greater good. What an idiot. These powers are only good for one thing, letting me take what I want, when I want. In a place with no law, the strong take what they want, and the weak are their slaves, their playthings. And no one is stronger than me!
Okay... But how does Evil Cole expect to rule supreme in a wasteland that will eventually lose all electricity? Bio Leech.
Good Cole has Blue lightning, Evil Cole has red, Kessler has white. Why? Because white is The neutral colour, and it signifies Kessler being Above Good And Evil, willing to do hideous things for the sake of everyone. He is unspeakably evil, for good reasons, but morality isn't important to what amounts to a Physical God.
It may also have something to do with the fact that if Cole uses the Ray Sphere, his lightning gets black. Kessler is the antithesis of the selfish, murderous, psychotic Cole who used the Ray Sphere.
Kessler's powers at the end of the first game are stronger versions of Cole's, but if he didn't have a ray sphere to amp him up how did he get them and his time travel power? Well: as of the sequel we learn that the beast that Kessler was trying to prepare Cole for was basically a living ray sphere...
Except Kessler had his powers before he met the Beast.
When Kessler shows Cole a vision of the future, Cole states that he knew he was responsible for the rampant destruction that would take place. Later, it is revealed that it's actually the Beast who causes it. Given how the Beast inadvertently comes about in Cole's timeline through Kessler's machinations, Cole was technically right.
On top of that, it's revealed that it's because of the Ray Sphere's creation that everything hit the fan in the first place: the plague, psychotic conduits, The Beast itself. And since Kessler went back in time to create the Ray Sphere early, he inadvertently not only caused all the bad shit to happen way earlier then expected, but also made things that much worse then in his timeline. He didn't know HOW The Beast was created of course so he can't be blamed, but it still presents the nauseating idea that if Kessler had simply gone back in time and made sure the Ray Sphere was never made, all of this could have been avoided...
Possibly. The Ray Sphere enhances/activates someone with the Conduit gene. It's hinted that Conduits develop powers naturally, which means that The Beast could have come about without the Ray Sphere, just much further down the timeline.
Kessler's ability involves giving people memories. So by this idea, he is actually giving Cole a memory of the destruction that happens in his own timeline. Since in his life he ran away from the Beast, he actually "caused" the destruction by running away from the Beast instead of stopping him before hand. Kessler did cause the death and destruction, just not directly.
We don't know how the Beast or Kessler got their powers in the original timeline, but the information given implies that the Beast was at least close to full power when he emerged. Even if Kessler was at the height of his powers then, he would have been destroyed if he tried to fight the Beast. Cole only survived his first encounter because the Beast didn't want to kill him. Kessler's claims of guilt ring hollow when you realize that there is nothing he could have done, and even after a lifetime of research in the second timeline, someone else created the thing that defeated the Beast.
At the end of inFamous, Kessler states that he could have defeated the beast back when it first emerged but chose to run away to protect his family. Hence why he kills Trish so Cole won't make the same mistake. By the time the beast caught up with Kessler, it was too powerful for him to handle.
Trish dies, no matter which building you climb. Normally this would seem impossible if you've played both outcomes of this mission. That is, until you realize that Kessler is Cole from an alternate future. He knows which decision Cole would likely make (even if he never did it himself)., and plans her death accordingly.
Kessler and the Beast are both considered Anti-Climax Bosses. Why? Kessler's entire plan was to make his past self Cole strong enough to defeat the Beast, which he was unable to. His plan succeeded.
The death of Trish seems, at first, to be cheating — no matter which building you choose, Trish will always turn out to be on the other one, the villain's actions retroactively adjusting to screw you over regardless of your choice. But after the end of the game, you realize Kessler chose whether to lie to Cole or not based on his knowledge of what Cole would do. By choosing what Cole does, you determine what is in his nature to do, therefore what Kessler would predict Cole would do, therefore which building Trish is on.
Word of God has declared that the hero endings are canon. At first, one would presume that this eliminates the evil endings completely, however, when Kessler's involvement is taken into consideration, there are really at least three timelines: the heroic Cole's, the infamous Cole's and Kessler's. Therefore, the bad endings could be considered "canon" as well.
Pretty sure they mean canon with iF2.
Regardless of whether you start with a good or bad save-game, the characters initially treat you as neutral before entering New Morais.