Never once has the story gotten convoluted, it has always been straightforward and linear. He doesn't plan more than thee weeks ahead? Are you being serious here? I honestly can't see how anybody would think that.
So you think Naruto would be a better character if he simply offed all the bad guys and gave up on his friends. Okay. I think you might have missed the point of the entire series. It is about the ''gutsy ninja'' doing his best to eradicate hatred from the world. Hatred is given form by the bad guys (However obnoxious they might be the Uchiha, Sasuke especially are the perfect example) and Naruto sheds his light on them. So yeah, the bad guys were all turned into bad guys because of the world they live in, Naruto is rejecting the status quo and I like him.
Sasuke comes from a clan with a genetic default that causes them to turn into power hungry madmen at the drop of a hat. He certainly has an excuse. As for people other than Naruto forgiving him when he turns up later....well, the enemy of the enemy is a friend. It isn't like they've let him back into Konoha with a clean slate or anything. I'd also like to add he has moved passed wanting to kill everyone now, if that means anything to you.
Other characters, dunno why anyone would hate Itachi. He'd be in my top 5 characters in the series for sure. Obito was just another world turned me cold guy and Madara we still don't know his motivation yet so I won't judge. Sakura is pretty awful I will give you that.