Go with your gut. It's like writing a story. Take what they post and make your character act how you want him to accordingly. You should be afraid to make things happen. One of the RPs I am currently working on was not created by me. I really don't understand the world we are in, but I am the leader of the RP. Most of the things that happen are because I make it happen. I really like making things happen. It's like you are the author of a story. It is really awesome.