StyledCowboy You can manipulate ST3 individual song volumes to a certain degree to even out your output levels, best practice is to leave alone the majority of your same level songs set to zero so the other minority that might be too loud or too soft are adjusted, this will save you time, you need to use your ears to determine your standard Zero level songs, if most of your songs are all over the place then you need to use external software to tweak them, some times normalizing on its own will not work as you might have high peaks that need compressing first to bring the average listening power up then normalizing to bring it up to normal listening levels.I never use bulk normalizing software as most of the time its not the normalizing thats wrong its the overall enery of the song that is different due to instruments used so there is a lot more to consider than normalizing.
But a simple tweak of individual song volumes mostly works for 95% of songs unless they have been totally unprofessionally made in which case i would never want to use them anyway as they are usually badly composed tracks.
Just incase you were not aware the volume control at the botom can be switched between song volume and overall playlist or queu mode make sure it is blue colour this will allow you to change individual song volumes and they will be remembered.