Starting a not-for-profit just to reduce your tax liability is a bad idea.
For a business in Iowa, the basic sales tax rate is 6%. Some locations in Iowa also assess an additional 1% “local option sales tax,” which makes the sales tax in that location 7%. Sales tax is not an expense of your business. Instead, it’s a tax you collect from your customers and pass on to the state.
Withdrawals from a 401(k) account are difficult if you're still employed by the company offering the 401(k). Withdrawals are allowed in certain circumstances -- such as to avoid foreclosure -- but are still subject to income tax and sometimes to the 10% early withdrawal penalty.
So why does the IRS care so much about employee vs. contractor? Two reasons. One is the penalties they can collect. The other reason is they usually collect more taxes when someone is treated as an employee, because a contractor can take business deductions which directly reduce taxable income.