Too confusing... too restrictive, and you do not have a full grasp of a workable agreement.
What you are basically asking for, or want, is to retain "rights of promotion" By retaining your rights and requiring your client to use a copyright statement. All it seems you are doing is putting tags all over the internet trying to enhance your web presence. Not even big firms require that...
There are a few books on the subject with sample contracts, portions of it dealing with copyright.
The main books are the GAG Handbook, "Talent is not enough", Design business books by Cameron Foote and there is a sample contract you can take portions of from the AIGA...
Make it stupid simple and quite asking for so much...