No he would not likely be dead by now. Had he stayed here, he would have been prosecuted for the original revelations, claimed and won whistle-blower status and been acquitted or pardoned. And that would have been the end of it. When he made his original revelations of the surveillance program he was a hero. That needed to be revealed, and his choosing to flee to another country to make the revelation is semi-understandable though less than the honorable act of standing by your actions when you reveal government wrong doing.
But!
Because he fled the country, and has to keep his value to his current hosts in order to retain his guest status, he's kept revealing stuff that has gone far beyond whistle-blower status. We the people did need to know that our government was collecting our data, and most likely in violation of the Constitution (gotta leave the final decision to the courts but I think it was illegal). But we did not have any need to know about our collection efforts directed at foreign leaders, even if they are allies. It's the Intelligence game, everybody collects on everybody, allies and enemies both. A political and Military Ally is still an economic competitor, and politically we don't agree on everything so even in that realm is there cause for intelligence collection. Neither did we need any knowledge of the UK surveillance program nor the Aussie program. Nor anything else he's released. And it was all those revelations that pushed him from Hero Whistle-blower to Traitor.
Had he stayed and faced the music he likely would have been acquitted by now as a Whistle-blower. We would still have had the national discussion about the surveillance program and even were he to be convicted he would be considered a Hero for protecting the Constitution. And had he stayed he likely would not have had the opportunity to dip into treason by revealing the stuff that did not concern us as constitutional violations.
We do owe him a debt of gratitude, but he ruined that by revealing classified information that did not concern violations of our constitutional rights and damaged our valid intelligence collection efforts. He has tarnished his Hero status and now stands as a traitor.