No, it's allowed, though some members frown upon it and leave negative feedback for accounts known to be bought and sold or associated with it.
Also, how do we know the account is not hacked or stolen which would mean we will lose it later on?
That's a big risk to take with our Bitcoins. Cause it's kinda hard to believe someone actually has 6 HERO accounts and he wants to also sell them.
Thanks!
You don't, but even if it wasn't hacked or stolen the person who sold you it can retrieve it anytime. That's the risk you take with buying accounts.