The binary code on Bender's apartment door, 00100100, when converted to text is the dollar sign ($).
Closing rap song, "went 187 on his robot ass." West coast rapper's use 187 for 'murder' because section 187 of the California Penal Code defines murder.
The episode's title is likely a reference to the influential blues musician Huddie William Ledbetter aka Leadbelly, known for his musical prowess as well as his criminal life.
Bender's blues name "Ramblin' Rodriguez" is likely a call out to Rodney Carl Anders, who hosted a local cartoon show in Matt Groening's hometown of Portland, Oregon. Anders went by the stage-name "Ramblin' Rod"