I hear the cracking.... subtle but there.... the track didn;t play well on this computer but I heard about 30 seconds of the track.
Is the cracking evident in the PLAYBACK as you listen? If not, it's coming in during the export..... If it's there in playback, find it in the tracks.... solo and mute the various tracks until you find it. then you may be able to envelope it out.... or you might need some other fix/solution to eliminate it.
If the playback is clean.....Lower your levels before you export.... pull the master output for the sound card down. It might be clipping on peaks... the track sounded good, but loud. Don't push the levels..... you can always make it louder later.... not that super loud is important. Artist demo just needs to sound good.
Mouth noise.... lip smacks..... breath sounds.... all that needs to be edited out in the track. It's not something that you try to fix in the mastering mix stage. I use envelopes and process audio mute to eliminate those sounds at the source.