Warren Buffett, the 94-year-old architect and face of Berkshire Hathaway, will hand energy executive Greg Abel the keys to a $1.2-trillion behemoth. Abel (62) will also inherit a plethora of questions, starting with what he’ll do with Berkshire’s almost $350 billion cash pile after Buffett largely sat out a volatile last few years. Shareholders will want to know how he will change the company’s idiosyncratic and lean C-suite, whether he’ll bring a different risk tolerance or industry preferences, and if it will remain the first call for companies in need of a big check and a vote of confidence.