Well, entrepreneurs are creating additional job opportunities for the economy at large. So if the tax cut creates a more favorable environment for entrepreneurship, there will be more entrepreneurs, and then more jobs should be available. Doesn't seem like the tax payers (who I assume you mean those whose majority of earnings are taxed under income tax rates) are really loosing out when they have more opportunity and a wider job selection.
Not as much as entrepreneurs who deal directly with customers - customers are less forgiving than bosses or PhD advisors. A boss may let you get away with not being productive if you're a nice enough person and trying hard to do your job, but customers want a product for their money.
