Those are all INFO messages, and can safely be ignored. RetroFE is merely letting you know which files it looks for, and which files it could actually find (or not). Random crashes like this are usually caused by problems with the gstreamer library, but you can easily check that by turning off the videos, and see if that solves your issue. Not all platforms have stable SDL and gstreamer libraries I'm afraid.
With regards to the Pi4, perhaps you should have a chat with the people who created the images for CoinOPS. They may have some useful information for you in that regard. I stepped out after the Pi3, and only run Linux on my PC platforms (cocktail arcade and laptop) I'm afraid, so I don't have a lot of experience with Linux on other platforms.