Don't get me wrong; I disapprove of the diving and misconduct.

But I am utterly unconvinced that in-game replays will make a difference.

In fact the main problem is the culture of footballers. Go back a few years and things are a whole lot more brighter. Men were men :D and the rules were the law. You are right; strict punishment for cheating would help fix that. Setting limits for player wages and so forth as well would be an important idea.