Okay, a little late to this party but I'd like to throw in my 2 cents.
First, with Otis and Shane, I'm not sure why everyone feels that this was such a villainous act. In the episode, Shane tells Otis to go ahead. Otis refused struggling with his own moral compass on leaving someone for dead. Shane however looked at the bigger picture. Carl needed the medical supplies and Otis refused to make sure Carl got those supplies and risked not only his safety but Carl's because he couldn't "Do what needed to be done". Shane couldn't outrun the walkers on his own, Otis couldn't carry him and the supplies, and ultimately Shane made the call to make sure Carl lived. I'm sorry but he made the only rational call he could. Otis forced his hand and ended up getting what he deserved. This is ZA world, not Disney World.
Second, with Carl shooting the kid, I for one don't believe for a second that the kid was doing anything BUT surrendering. He's a kid, not a solider. The fact that 2 armed people chased off some 20 plus people who were fully armed themselves shows this. I don't think when the people of Woodbury came along, they were going to be doing more than just being a show of force. The Governor obviously thought otherwise but then he isn't in his right mind himself and when reality smacked him in the face that these people were just liabilities and NOT the army he thought he had, he snapped and cut his losses. In so far as "But he didn't drop his gun", the kid was already pissing his pants before he ran into them. I think he was moments away from dropping to the fetal position and crying for mercy cause even if he wasn't scared, he had two guns on him (Hershel as well) and he never would have succeeded in any funny business anyway.
However, did Carl shoot that kid in cold blood? Yes. Does that make him deranged and a sociopath? Nope. Let's face facts, they attacked and no one was taking prisoners. Would he leave and never return or will he be back again tomorrow ready to shoot Carl? What Carl did was basically the ZA world version of the saying "Better safe than sorry" Didn't Rick do something similar when he had to drive an Axe into Tomas's Skull after one too many "Accidents"? "Better safe than sorry" except in that case, it was a lot more clear that Tomas had to go.
Andrea had to die. Not because she was becoming Dale but her constantly stopping to talk and look at Milton to see if he was a Zombie was the most unrealistic thing I've seen in the series so far and I'm glad I won't have to see it again.
The one thing I feel for sure that is season three was leaps and bounds better than season two. OMG was that one brutal. Other than Otis's death and Sophia's death (Which thankfully happened.... another "needed to die for making the audience suffer" character) season two was really one to just forget about. Other than that, I'm sure civilization is still out there somewhere.... after all, if the apocalypse happened in 2010, then someone is still making cars out there cause they are driving a 2013 indestructible mini van. In season four, they are going to come across an overturned Dr. Pepper truck.... Calling it now!