Anything Goes : Should an actor have a manager? by Bryan Casserly

I recently got a message on twitter from a manager that expressed interest in meeting with me based off what he saw on my acting website. I already have an agent so I wasn't too familiar with what exactly a manager does. We met early this week and he seemed very excited to work with me. When I got home later that day he had sent over a contract that would give him the rights to 10% of everything I earn as it relates to the arts. I read the contract and naturally had some questions for the guy. He used the words "advise and counsel" and "reasonable effort" the wordage of that made it seem vague as to exactly what he was going to do for me. So I asked to speak with a list of references "artist clients" and said I need to know what you do for me is equal to what I'm going to do for you. He responded by saying because of that comment I am not ready to have a manager, and that he is taking the majority of the risk. Also he never offered to give me a list of references. Does an actor really need a manager? If so, how exactly can they help a young actors situation?