There’s a long list of people in Hollywood who swear they’ll never work with Kevin Costner again. And they all have their reasons. He doesn’t always pay his bills on time — one since-settled lawsuit alleged hundreds of thousands in unpaid costume fees. He burns through relationships — like his longtime producing partner, whom he sued for $15 million. He ignores advice, even from folks like Steven Spielberg. He rewrites scripts without warning, overrules directors and on more than one occasion has clashed with his co-stars — including Clint Eastwood, Kurt Russell … and Wes Bentley. The Oscar-winning director and actor is brawling with his castmates, getting sued by his crewmembers and, in recent months, giving paid keynote speeches at bakery and veterinarian conventions. And behind it all, according to several insiders, are power struggles playing out far from the spotlight — ones that some say have left even Costner himself in the dark. All of which raises an obvious question, the on...