@Elliot_The_Idiot There is an issue in the latest version where camera transformations will not display correctly on other layers, and this could be what is causing your issue with the white frames around your images. To fix this you can select your camera layer, go to each camera keyframe, and from the top menu to to View > Reset. To understand the camera layer and why you are getting this behavior, I recommend you look at our camera layer guide.
As for the audio, unfortunately some people have reported similar issues of differences in the audio syncing and we have been unable to completely fix them. If you are not using v0.6.6 of Pencil2D, first try updating to that as it has some improvements for this issue. If you are already using that, the only thing I can recommend is to try using the sound scrubbing (it is toggled with a button on the timeline that looks like a speaker with an S). Theoretically it should be closer in terms of timing to the exported audio than what you hear during the preview playback.