Well let's call it what it is. You want a revenue tax on corporations. The obvious point is: high turnover businesses that make profits through volume would pay

Well let's call it what it is. You want a revenue tax on corporations. The obvious point is: high turnover businesses that make profits through volume would pay a disproportionate tax - a tax which ostensibly is to do with liability insurance, but doesn't correlate with the things that are likely to incur liability.