no
Probably Camilla within the family. In public her titled name.
Yes, one would curtsy or bow to Camilla, as she is the Princess of Wales(she doesn't use that title, she uses the title Duchess of Cornwall)
When or if Prince Charles becomes King Camilla will be Queen Consort but has expressed wishes to be Princess Consort instead out of respect to the memory of Diana, just as Catherine will be Queen...
The little girl holding Pippa Middleton's left hand, the one with straight hair.