No
You would capitalize that word however you use it.
The pronoun,I is always capitalized.
When the Queen knights someone, she typically says "Arise, Sir Name, and be recognized for your service and achievements."
No it shouldn't be capitalized in this instance.
Yes, "Internal Revenue Service" should be capitalized as it is a proper noun.
No, "memorial service" is not capitalized unless it is at the beginning of a sentence or part of a title.
This means exactly that. Thanks, for whatever gift/service was given.
Yes, President is a title just like professor. Its acceptable to not capitalize these words when they are not describing someone. EX: the history professor is really difficult. But when it is not a noun, and is however, a pronoun you should capitalize it. With the exception of President and Doctor. These should for the most part always capitalized.
At the begaining of a sentence, and the first letter of someone's name.
Faith is not a proper noun. If someone is named Faith, then it is capitalized.
You only need to capitalize the word "billion" if it is the first word of the sentence...or if it is actually someone's name, or any other proper noun.
You should capitalize "American" when referring to the nationality or citizenship of someone from the United States, as in "American citizen." However, you do not capitalize it when referring to general concepts or things relating to America, such as "the American culture."