What's the third move? I would recommend both STABs + Thunderbolt/Thunder + HP Ice on most sets, though HP Fire is also an option. I find Stealth Rock sets to be not as good as Scarf.
Venusaur isn't such a big problem imo and Psychic is poor coverage against typical Nihilego switchins such as Steels, so yeah I'd run with Tbolt or HP Ice for sure.
Yeah, it was more thinking of a SR set, but I'll definitely consider doing an All-Out Attacking set with Power Gem/Sludge Wave/T-Bolt/HP ice.