Without proper system information and other details such as exact versions of the programs, audio settings etc. nobody can tell you much.
the system I use to edit video is my apple imac with 1tb of data, OSX Yosemite 10.10.5, 16gb ram, NVIDIA GeForce GT 750M 1024 MB graphics
the audio settings are 48000hz and the display format is audio samples.
you will most likely need to use the Panasonic tools associated with your camera to convert your footage to a usable format. Try a Google search or start here:Software Downloads | Professional Video | Support at Panasonic