Riven is optional: (Without I'd go with [Tactical Pump])
This was a cheap Riven, bought under 50 plat, the stats I value most here is reload speed and punch through, any damage related stat you can roll on top is a nice bonus.
And of course the extra status chance is just a nice bonus (but not optimal), just helps with procs whilst we exclusively use flat damage elemental mods.
I would prefer multi-shot in place of that, and to roll a harmless negative to boost our positive Riven stats.

Shotgun Vendetta arcane is also optional:
This brand new arcane is a god send for this weapon because the reload stat is super important for this gun. Without this arcane you're gonna have to make up for that low reload speed by using [Chilling Reload] in place of [Primed Chilling Grasp], which is gonna hurt your damage numbers. Then use the Primary Merciless arcane instead.

Don't feel bad about making any of the above compromises, as this weapon still performs excellently that way. I used to run it a lot like that before I got the riven and arcane.