All he had to do was stop writing names for a while after L very publicly announced that he was narrowing the search area. It's his own ego that pushes him to come up with elaborate ways to hide what he's doing as the number of suspects dwindles.

As soon as he learns that you can affect the time and manner of death, he could have made all the rest seem like accidents, spread out over years. Again, it's his own ego that gets in the way; he wants people to know the deaths are connected.

I think it detracts from the main premise of a detective show. Not that it becomes automatically bad; all the other characters carry it enough. But it would be a truly great show if Light was as intelligent as he is presented to be.

As it is, Death Note is less of a detective show involving supernatural elements, but a show about supernatural involving detective elements. The story I got from it wasn't of two masterminds clashing in a battle of strategy, but of a vulnerable teenager being used by supernatural entities for their amusement. Which makes me feel misled.