I'd say so: it is a proper noun.
No, "line manager" is not capitalized when used in a sentence unless it begins the sentence.
No, "personnel" is not capitalized when used in a sentence unless it is at the beginning of the sentence or part of a title.
No, the word 'world' is a common noun. A common noun is capitalized only when it is the first word in a sentence.
Conjunctions used in the titles are not capitalized except if it used as the first or last word of the title but it is capitalized when used in the beginning of the sentence.
No, "sister" is not capitalized in the middle of a sentence unless it is used as part of the name or title that is capitalized. For example, in "I have a younger sister," "sister" would not be capitalized.