Most of the things you've listed here are not problems that occur exclusively with Bitcoin or cryptocurrency.
These are just things that happen due to human nature, so unless you can find something that would make human beings less greedy, I don't see how this can be fixed.

It might be a bit negative of me to think this, but I really don't see how you could completely eradicate scamming and cheating.
Maybe in future societies things like this won't exist anymore, but it'll take a massive shift in attitude to solve it.

There are countries where you see extremely low crime rates, Japan comes to mind, but crime still exists even there.