Soldato
This speaks volumes. You could have just written that.
To be fair, there's actually one (IMO) very good Neelix-centric episode - "Jetrel", in the back half of VOY's first season. It's partly the atomic bombing of Japan IN SPAAAAAAAAAAAACE but with a Treknobabble plot about maybe being able to save victims from this earlier incident, along with a nice character piece on coward vs. conscientious objector, how it feels to be confronted by the monster who caused you great pain in the past but is now seeking redemption, and what it's like living with the choices you made.