As brilliant as you think you are, I'm a tech writer who works with computer and software companies. Believe me, these companies use the phrase "mouse devices" to avoid the sticky plural argument.

Ahem. That should be "manually-operated user-select equipMENT." Sorry!

This is a tough one, because there really is no official ruling on this usage yet. Computer companies usually avoid this problem by using the phrase "mouse devices" instead. I would advise the same strategy if you mention the equipment in a formal paper, article, etc.

Since neither "mouses" nor "mice" is the official plural of "computer mouse," using either one is acceptable. Technically, since "mouse" is an acronym for "manually-operated user-select equipemtn," it sound probably be pluralized as "mouses." But since hardly anyone is aware of the word's etymology, and because it sounds less awkward, most people pluralize it as "mice."

With your reasoning, answering the question "Who won?" or "Who is the winner?" with "I." would imply "I did." or "I am." Therefore "I." is the shortest sentence.

No, because "I" is simply a subject with no predicate. What David says is correct; in commands, there is an IMPLIED subject. If I told someone to run, I wouldn't necessarily say, "You run." I would just say, "Run," and the "you" (the subject) would be implicit. A subject can be implied in a command (mandate); a predicate cannot be implied.

Inside the quotes. It doesn't matter that "hunker down and protect turf" is not, in itself, a complete sentence. American usage dictates that commas and periods ALWAYS go WITHIN closing quotation marks, except when a a parenthetical reference or citation immediately follows the quotation.

For the record, colons and semicolons go outside closing quotes; placement dashes, question marks, and exclamation points depends on whether or not the punctuation applies to the quotation itself (inside) or to the sentence as a whole (outside).