personally my QS uses yellow gems on main weapon, my running shot damage goes up to 13-14k
what i found is that running shot DOES affect critical damage, its the only thing that makes sense why my damage is so high since i only have 1.3k physical attack on this char and 1k critical attack
so yes, running shot DOES multiply critical attack
1k critical attack = 2800 additional damage with running shot and 3200 damage if you have the running shot gem i am certain of that.
There is a chance that red gems would still provide more TOTAL damage in some cases, but tbh yellow damage is high and steady i like that, stays in the 13-14k range, not like one hits 7k and one hits 17k
also i just realized that how lucky i got with enhancing
damn +10 without failing once