More than likely, there was damage to the wiring for your pass headlight and running light. I would pull the whole pop up assembly out and check the harness for the headlight and marker light. More than likely, the harness got sliced/disconnected shutting the headlight and marker circuits down. The combo lamp (as the marker/running light is called) has two power wires and one common ground. One power wire (Red/blue) is for the running light (dim) and the other wire, which I can't remember the color of hand, is for the turning signal (brighter).
Normally I'd say it's a ground, but your turn signal still works, leading me to believe it's a power supply issue.
As for the speakers, you got me on that one. A frontal impact shouldn't damage the audio wiring, unless you were running some monster cable for an amp.
Also, If you're any good with wiring diagrams, make yourself friendly with the EL section of the service manualhttp://
www.240edge.com/manuals/91-94_240sx/el.pdf
In particular you'll want the "Power Supply Routing" page and the "Audio" page. If all the associated electronics are down that are fused along with the radio, you can bet it's an issue with power routing. Nissan runs the power line from the battery to the passenger fusebox, then around the front of the car into the driver side kick panel where it goes to the key cylinder to branch into ACC ON START. The Blue (L) wire is routed from there to the indoor fuse box and then on its merry way to its final destinations.
I doubt that would be the case though because I assume your car starts.