I edited my title screen a while back. You can edit the logo and background images.
I still have the link for the documented file paths and true file names of the images in case we want to change images rather than edit them:
As for the voice lines, there’s like thousands of them and all of them are named in hexadecimals so it’s incredibly difficult to specifically find the audio files you wanted, especially voice lines.
At least it’s somewhat easy to find music files since they’re usually larger than most sound files.