Harry Potter is quite punk rock, when you think about it. He was a rule breaker - sometimes to a serious fault - but he was the kind of wildcard that was needed to take on not only Voldemort but the institutional corruption of the Ministry Of Magic. Sometimes, it takes a supposedly "bad apple" to take care of the rot.
But was Harry really all that bad? He gets a bad reputation these days for being a bit of a dick, thriving on praise that should have gone to other characters and generally acting both like a brat and a danger to others, but that's sort of to be expected. Not only was Harry the product of intense, inconceivable trauma, he was also literally infected with a slither of the most evil wizard of all time's soul. The fact that he was able to resist being outright evil is actually pretty remarkable.
That said, he did also pull some unforgivable sh*t in his time at Hogwarts - and indeed beyond - and a lot of it gets forgotten JUST because he saved the world. It's one rule for the Boy Who Lived and one for everyone else. Incidentally, some would say that he's also out of order for dating his best friend's sister, but Ron doesn't own Ginny and she can make her own decisions. He's done far worse than that...
10. Got Sirius Killed
To create a good hero, you have to sprinkle in a bit of a roguish element along with a strong moral code. You have to be willing to bend rules for the greater good, in other words. Unfortunately, when you're a petulant, volatile child with a history of making overly emotional mistakes, you can also fall into the trap of wrongly identifying what rules to ignore.
Take Harry ignoring Snape's Occlumency lessons despite Dumbledore's insistence, simply because he didn't like Snape. As well as spying on his most personal moments, Harry sabotages those invaluable lessons through apathy and gives Voldemort the key to trapping him in the Department Of Mysteries. He didn't cast the fatal spell on Black, but if he'd just paid attention properly, he'd still be alive.
And on top of that, he also failed to look after the mirror Sirius gave him - the most precious of gifts from the most precious of people - which would have allowed him to make sure he wasn't in danger. It's just idiotic.