why not you use client more latest compare to 20120412 ? that was quite too old for now.
lua files errors might be related to accessoryid, or accname. make sure you have both added correctly.
about the palette, make sure you read the instruction, you might need the corrected sprite for it.
and for the npc, since u are using updated rathena, try to use the clean one maybe. I suspect your script having issue or wrongly coded, thats why.
clean latest rathena : https://github.com/rathena/rathena
and the sounds are most probably from client side too.
Try to use client 20180620 at least maybe, then most of the tutorial or solution here might helps.