Heaven's Door is a stand that controls the mind, however, it's less like brain washing, and more like hypnotic suggestion. The idea is that Rohan can make you do anything he wants, so long as it's within your ability to do. He can tell you to grab a lighter and set yourself on fire, because that is a possible choice you have and can decide to do. But he can't tell you to grow wings and fly, because that is impossible for you. It can only make you do things that you can already do. Knowing the location of someone you've never heard of is not something you can naturally do, therefore Heaven's Door can never make it happen.