To clear up a misunderstanding that some people may have, the tax rate only affects private corporations and the profit transfer rate only affects state controlled corporations.
You really need a 0% tax rate to attract investing CEO's if you're interested in setting up a CEO-based economy. Given that the amount of income you make from enterprises is WAY larger than the amount of income you make from taxes, it really isn't an issue. I have one very small country on FB that has it's tax rate set at 75%. It still makes 19B/month from enterprise income, and only makes 2.5B/month in income taxes.
Profit transfer is the percentage of profit that a state corporation will automatically transfer back to the state every month. I've never found a reason not to set it to 0%. Whenever a corporation has a surplus of monies (I believe it's somewhere over the 40-50B range), it automatically transfers cash back to the