if time stops shouldn't it have infinite speed?[/b]
If time stops then the speed of everything is zero.

yet i have seen calculations for the exact amount of joules needed to make a ship go at the speed of light even though the ship would have infinite mass.[/b]
Those calculations will be ignoring certain laws of physics. You probably read a shock-statistic designed to help you understand the speed of light rather than accurately portray what would happen to an object at that speed.

does that also mean that there is infinite mass in the universe if there is light?[/b]
Einstein was referring to objects of mass, not waves like light. Light is not an object.

if we go faster the "C" the speed at which time stops will we go back in time? [/b]
Such scenarios are beyond our ability to mathematically model. Besides, that statement assumes certain things about time which are not certain. Our view of time is designed to help us live with time, not help us understand the true nature of it.