Can you start an engine to inspect a timing belt with the belt covers off?

I just replaced my timing belt and the car will sputter every first start when it sat for about 5 minutes, I know all timing marks are lined up and so on belt is tightened to factory specs, how do you tell you have a bent valve possibly I don't want to take the valve cover off if I don't have to but is there any ways to tell a bent valve, and can I start the engine without the timing belt cover?