On top of all that, Sylveons Hyper Voice hits through subs, so thats also a thing.
Zekrenzo
The most common walls are Chansey, Mega Venusaur, Heatran, Quagsire, Skarmory, Gliscor, Mandibuzz, Tyranitar (more of a tank tbh), and Zapdos (I might be missing a few, idr). I'd suggest looking at the OU viability rankings, as they link to the analyses of each.
As for stall breakers, you have Taunt Thundy, CM Lando, Mixed Megachomp, and Gothitelle. Like the walls, I'd suggest looking at their analyses for their most common sets.