For correct legal advice you need to go to a lawyer or good law source (like Nolo press). But in general unless you are in a state like California which I thin

For correct legal advice you need to go to a lawyer or good law source (like Nolo press). But in general unless you are in a state like California which I think makes this kind of assignment of rights impossible you are correct in reading this contract as killing all of your rights. Even in California most of the employment contracts I have seen lay out some limits (like on company time, machines or directly related to the business). Overall you may or may not have rights (depending on what state or country you are in) and on top of that you may or may not have lost your rights depending on what sort of contract you have signed.