Circumcision is done for religious reasons, so I really don't even want to touch that one!
No males in my family are circumcised (we're Buddhists), BUT, all the uncircumcised males I know said they wish they were circumcised (for asthetic reasons). That's food for thought
In regards to dewclaws.... I think certain breeds definitely DO need their dewclaws removed for their own safety, namely the digging breeds. My parents have a coon hound/beagle cross that loves to dig, and one time she nearly ripped her right dewclaw from snagging it when she was digging.