Certificate of Application (COA) for an EEA4 application

Does the COA entitle me to be self employed? or it only allows me to accept employment?

I might move house. I used to see a form on the website of the UKBA which I could fill in my new address, but could not find it anymore. It seemed to me that the UKBA has edited their website. Where can I get this form? or I will need to call the inquiry line to update them over the phone?

Thanks