In the fights where he has lost or been given all he can handle, opponents that are patient and make Pac be impatient take advantage of him. Morales and Marquez had Pac diving in trying to land big punches and took advantage when he did. I'm sure Pac has changed since then, but he will still be susceptible to counter punchers that make Pac chase and dive in.
he's not the sharpest knife in the drawer.
he has too many idiots around him.
he is an awful singer.
he wants to be a politician and probably will be an awful one.
he's a primadonna.
flaws?
he's part korean...