Why tax corporations at all? It's not like they're a magical pot that you can tax without taxing people. People disagree with how much corporate taxes fall on consumers vs shareholders, but if what you're concerned about is equity you can pretty easily target an income tax hike toward rich folk.

I'd say taxing corporations is a fool's errand anyway, because they'll always have the resources and the centralized control to figure out how to escape taxes as much as possible and carve out further special tax breaks for themselves. Disaggregate individuals can't do that.

Limited liability is one externality that needs to be corrected for, but the idea that it adds up to hundreds of billions of dollars strikes me as implausible.