Using IRS form 4070: will using it put my coworkers/employer at risk of being audited, if no one else submits it?

Why do you ask? Why do you think that would cause an audit? See this IRS help topic:
<a rel="nofollow" target="_blank" href="https://www.irs.gov/businesses/small-businesses-self-employed/reporting-tip-income-restaurant-tax-tips">https://www.irs.gov/businesses/small-businesses-self-employed/reporting-tip-income-restaurant-tax-tips</a>

Simple answer: No.

The 4070, like a W-4 , only goes to the employer, not the IRS. 

It also the law that you must submit the form 4070 (although it is frequently ignored).  Without a  4070 from the employee, the employed is required to assume you got a certain amount of tips and include it on your W-2 (box 😎