Funimation WAS rather inconsistent with editing. They couldn't even decide whether or not to censor out mentions of death and, in spite of recoloring non-red blood to skin color throughout the series, Cell's blood wasn't censored when he was taking damage from Gohan. It was still purple and it very much contrasted with the skin around it.
Yeah, those Nephrite's death would be hard to edit. At the very least, they'd edit the part where he's pierced. Although, I saw Nephrite's death in DiC's dub before I entered sixth grade and it barely had an effect on me then since I was aware of death then. If I, an kid with asperger syndrome, could handle it then, I see no reason why others couldn't.
Honestly, if soccer moms believe their precious little angels (at age 10 or so) will be traumatized, why don't they ask their kids if what they saw bothered them and how? Is it so hard for them to act rationally?