Looking over the code, I do not think those settings should have an impact. Visualizations are essentially a secondary sink at a fixed 44.1khz, with the audio buffer being resampled if required.
I think you're right. After looking at x86-64 and RPi crash logs again, both have segmentation faults:
Code
Core was generated by `/usr/lib/kodi/kodi.bin --standalone -fs --audio-backend=alsa+pulseaudio'.
Program terminated with signal SIGSEGV, Segmentation fault.
So probably the memory stack of the audio was corrupted by bad MP3, and later GUI sounds lead to a crash on RPi.