Emo = emotional hardcore. Stating that an emotional hardcore band is not emo is retarded, they are interchangable terms.
Darkest Hour are melo-death, not metalcore.
These Arms Are Snakes are ok, but the first track on the ep is far better than the rest, which is fairly irritating.
Coheed and Cambria are fucking amazing, as are the rest of the bands on my list. You might not like those bands because they actually know how to use melody to make catchy music which is not too catchy, but I value that attribute. Sure they are a bit poppy, but since when is that a bad thing?