You are be able to upload any tracks with any bitrate using the uploader tool built into Live365. You might have some tracks with a bitrate of 128k, and some at 192k.
Bitrate effects sound quality. The higher the bitrate, the better the sound quality will be. Our system will transcode the files to deliver a constant stream to listeners and that will help to slightly normalize the bitrate. Higher bitrates might be perceived as marginally louder, but not significantly so. Currently Live365 does not do any volume normalization.