(Forbes) —Entrepreneurs can’t completely inoculate their businesses from the vagaries of the market. What they can do is wrestle with the fundamental questions that govern the fate of any enterprise. We’ve done our best to compile the 20 most important ones. Digging for those answers is a grueling exercise–one that takes serious intellectual and emotional honesty. With any hope, the process begins long before money’s been spent, products are built and customers are lost.