Understand that I do see where you are coming from. I say this, because I'm getting the impression that my tone might be coming across as rude rather then the respectful tone I intend. Tone doesn't translate well via text.
The name Light is hardly a common Japanese name either. Far as I know, not a single Japanese person has ever had that name. Though you never know what some otaku's will do. I read a story recently where a guy on Facebook is planning to name his child literally "Batman". I could see an American audience accept the name Light for a movie. That reminded me of a story about this couple that were only speaking Klingon in front of their new born child so he would grow up with that as his basic language. I heard a Judge stepped into the middle of that.
You still get symbolism naming the character after a biblical figure. Not as heavy handed, I agree. As a writer you are expecting people to believe writing a name in a book could somehow take a life. Light isn't that much further.
As someone who read Death Note and enjoyed the anime (side note: that was one of the very few times I think I enjoyed the dub more then the original Japanese dialog). I hear this kind of story and it has L, but not Light. I get it into my head that this is just a simple Kira wannabe. Such as the one Near dealt with in that final Death Note book. The guy that was killing the sick, but took his own life.
I think you really miss some of the layer trying to turn this series into a movie. One of the most interesting aspects of the story was that both L and Light knew who each other were. L lacked the proof he needed and Light lacked L's real name. It was very much a batle of wills as they danced around each other as if they were friends. All the time testing and prodding each other. I loved that moment where Light thought he had won when Misa saw L's real name and tried to call her, but L had lifted her phone.
Without that tension it's just another suspense drama of a detective trying to stop a serial killer, but with a supernatural twist.