I don't want to pick, but below is a more accurate rendering of your paragraph into King James English.

If thou dost desire to shew how practical the King James Bible is in high school, thou shalt practice the language thereof. Thou shalt hand in reports to thy teachers bearing witness to the beauty thereof. When thou dost give reports before the class, thou shalt suffer thy peers to see thy love toward the King James Bible by thy words.

Want means lack in Elizabethan, either desire or list is the word you are looking for, desirest is second person and desireth or listeth is 3rd person. Listest is not found in the KJV but I suppose is the proper second person of list. Doth is third person for does, but dost is second person. If you use doth or dost before another verb, the second verb needeth not be conjugated. Hence, you would say "dost desire" or "desirest" but not "dost desirest." So also hath is 3rd person and hast is second person. Shalt is 2nd person, shall is first and third. Art is second person, are is third.

Thou is singular nomative, thee is singular accusative. Ye is plural nominative, you is plural accusative (and nomative too it seems). Nomative simply refers to name and means that you use this form when addressing a person or persons as the case might be. Accusative means it is the object of the verb. So, you would say "Thou art my friend" and never "Thee art my friend." Also, you would never say "I will give this to thou" but rather "I will give this to thee." So also, "I will give this to you" and not "I will give this to ye." However, both "ye are the people" and "you are people" seem correct.