Differences between right and left handed people
According to this Psychology Today article: 3 Myths and 3 Facts about Left-Handers (with numerous links to many papers throughout the article), there are no particular difference between left and right handed people in terms of intelligence, personality, creativity or mortality.

There seems to be a noticeable difference in the number of people having the language centre being in the left hemisphere of the brain (95% for right handed people vs 70% for left handed people).