Hard-driving: Kirk is a leader who pushes himself and his crew beyond human limits. 
Charming: In one screenplay, Kirk is described as charming and witty at age 22. 
Dangerous: In one screenplay, Kirk is described as dangerous and rebellious at age 22. 
Other characteristics 
Kirk is a decorated Starfleet officer who served as the captain of the USS Enterprise.
Kirk served as an explorer, soldier, diplomat, and time traveler.
Kirk is one of the most famous and sometimes infamous starship captain