Was the OP ridiculing the Christian faith? I didn't read it like that - I thought OP was just questioning.
In answer - as others have said, the Romans weren't likely to get the whole execution thing wrong (ever), and particularly in this case with a high profile prisoner, politically provocative, caused a lot of disquiet amongst the high profile Jews at the time. The 'blood and water' which came out of his side when they cut him with the sword is (apparently - I'm not a medical type) a sure sign that he was actually dead.
'Super human' strength in a healthy mum who rescues her baby from a tiger is one thing, but would be quite another thing in a man who had been flogged (the Roman wips had bits of metal embedded), made to carry a massive plank of wood up a hill, cricified (and so basically suffocated), and would have had massive blood loss, and then had a sword thrust in his side, and was then wrapped up (as was the custom) and put in a cave.
So he would have had to recover from all of that, unwrap himself, move the enormous stone which would have taken several healthy bodies to move, then overpowered the (armed, healthy) guards.
Or if his followers had stolen the body, they would have had to overpower the guards, and thats a story which would have turned up in the history books as an historical event. The Romans were a vicious lot. If the guards had have fallen asleep/gone away, they would have been executed themselves I believe (as was the punishment for slack soldiers).
As someone else above pointed out, it doesn't make sense for the followers to have take and disposed of the body. Jesus closest friends were mostly killed for their insistence that Jesus had risen, in the few years after Jesus' death - they would surely have changed their story, and produced the body to escape death. Or the romans would have been looking for the body (or indeed would the Jewish leaders, who had more reason to hate Jesus than the Romans did). But no body was searched for or produced.
As for the idea that Jesus didn;t exist at all (I know the OP didn;t say that - was another poster) - whoever believes that is pretty well alone in that belief. Again, to reiterate what others have said, there is more historical verification for Jesus existence (and many other facts about his life, where he lived, and what was believed about him at the time) than there is for Julius Caesar, for example. The fact that Jesus existed is not really debated by historians, though of course his Divinity is hotly contested and always will be.
I second the reccomendation of the book Who moved the Stone? to anyone who is really interested in getting to the bottom of this though. And it is worht getting to the bottom of.
If Jesus didn't rise then Christianity is a sham. And if he did rise then it has serious implications for all people. There is no room for middle ground "he was a nice teacher", because if he wasn't God and didn't rise from death, he was a dangerour nutter, not a nice teacher.
Happy Easter OP :)