@David-Kissam You can get the peak level of any buffer with Buffer.getMagnitude()

As for the batch processing, I'd say load your audio files into an AudioLoopPlayer (or something else maybe?), then Engine.renderAudio(). From here you can (I haven't tested in this configuration) get the magnitude of the buffer and use it as part of the file name.

And for realtime audio recording I have published a snippet recently (but the search in the forum is somewhat painful currently). There's also a recorder example in the Snippet Browser