Part 2: The origin of Trip's character from the original story.
Xuanzang, the character that Tripitaka (this name comes from the name for the earliest known Buddhist texts) is modeled after, is the original reason the Journey to the West story exists. Being very religious from a young age, he studied classic Chinese literature and delved deep into the meaning of Buddhism. Because of this, he decided that he wanted to seek out more information -- his quest to find sacred texts of Buddhism led him from the city of Luoyang in China to India, a seventeen-year-long journey. Upon his return, he translated about 1,300 articles of Sanskrit Buddhist text into Chinese, and his translation of a particular Sutra (the Heart Sutra) remains the standard for East Asian Buddhism. He also founded a school, Faxiang, whose philosophies would later find their way into other schools even though Faxiang itself didn't last very long.
Wu Cheng'en, during the Ming dynasty, would later take his story and turn it into the classic Chinese text Journey to the West, with a lot of obvious changes.
First off, if you're looking something much closer to the original text, i.e., something that adheres to a similar plot structure, read the Saiyuki: Journey West LP.
The original story begins with Xuanzang receiving a visit from the bodhisattva Guan Yin, who tells him that the lands of Southern China are a bog of hedonism and sin, and that only Buddhism will help clear the darkness. Guan Yin tells him to take Buddhist sutras from India and bring them back. The world of China described in the story is fantastical; Xuanzang frequently encounters demons and all manner of supernatural beings.
His first encounter is with Sun Wukong ("awakened to emptiness"), and upon freeing him from his entrapment by Buddha for defying Heaven, Guan Yin places a magic ring on his head (i.e. Tripitaka placing the headband on him). Instead of activating it from a console, or manipulating his vision at all, Xuanzang can only chant a Ring Tightening Mantra which helps keep Sun Wukong in check; despite his intelligence, Sun Wukong is an incredibly violent god, but extremely helpful to Xuanzang throughout his journey.
Anywho, making the Xuanzang character a female isn't as out-there as it might first seem. Saiyuki: Journey West gave you the option of making Xuanzang male or female, and this is because the translation of Journey to the West in Japanese ("Saiyuki") leaves Xuanzang's gender very ambiguous. Although recorded history has Xuanzang as a male, the translations of the story have muddled this.