I cried so much when Tara died, it was so sad. It had me depressed for a long time. Why did she have to die, she was the most innocent character and my favorite. That guy deserved to be killed by Willow.
"That Guy" aka Warren Mears, was grappling with some major psychological issues. He couldn't understand the impact of his actions or the seriousness of death. He needed mental help, but he did not deserve to die.
He's not dead though, that flash of fire and his disapearing was actually Amy's doing, and she's been keeping him alive all this time. The First was able to take on his form becasue his heart stopped breifly after he was skinned but he's still very much alive, albiet also very skinless. Go read Season 8, it's really good.