Silence.
The girls name is Misa Amane and i believe it is episode 12
The death note reference appears in Episode 14 of Yu-Gi-Oh Abridged by LittleKuriboh. In this episode, the character Marik uses the Death Note to write Yami's name, referencing the popular anime series Death Note.
There are 37 Death Note episodes in English.
Episode 29, 'Father'.
episode "19" 5 minutes in
The song is Semblance of Dualism from the second Death Note soundtrack, composed by Hirano Yoshihisa and Takeuchi Hideki.
Episode 28
Every episode of Death Note is dubbed in English. You can find them on DVD or on iTunes. The two director's cuts are also available.
L shows up in episode 2.
The episode when L dies, 25
Episode 32 for about a second and episode 35.
The last half of episode 20