1. When you start chelating your body from remaining mercury, you need to make sure that the source of mercury has out (get rid of all that occupying your teeth). In your upper teeth case, you need to check whether your root canal has mercury in it or not.
2. I don't so I can't answer that :P
3. I don't have partial yet (will need to have when I get rid of my root canal I guess), but one of dentist I asked recommended valplast (www.valplast.com) for metal-free partial. However, even though this is metal free, you need to do thorough sensitivity check to see whether your body can handle this material.