According to the Chicago Manual of Style, it's "e.g." and it's not italicized. It's an abbreviation, so just as you would abbreviate United States to U.S., you do the same with e.g.

(I mention the point about not italicizing because e.g. is an abbreviation for a Latin phrase, and foreign language words and phrases are sometimes italicized. However, when they are very common—e.g., "nom de plume"—you don't italicized. Such is the case with e.g. and it's cousin, i.e.

Both forms are correct; generally, you find the -s ending more prevalent in Great Britain (or among British English speakers), and the shorter form more commonly in the US. There's a similarity with "toward" and "towards."

AnWulf is correct. The proscription of sentence-ending prepositions is a shibboleth that has been tarred, feathered, and burned at the stake for HUNDREDS of years.

In the 19th century, someone (sorry, don't have time to look up the scores of references) decided it was a bad idea to end sentences with prepositions. Somehow, that caught on with way too many English teachers: There is nothing wrong with it, and never has been.

You might want to check Google or Bing for "grammar blogs" and follow a few of them: They're quite enlightening!

Generally, ordinals are not used with day of the month (Chicago Manual of Style, 16th Ed., 9:32). When writing just the day of the month, generally, the day is spelled out; otherwise, use cardinal numbers:

My birthday is August 26.

We are flying to Florida next month, on the fifteenth.

In your example, "the August 1 card" is more correct—in both Canada and the US.

Afraid I have to disagree here. "Who knows?" is rhetorical question, and when I say it out loud, my inflection rises at the end, indicative of a question (and therefore, a question mark). Otherwise, you're saying that someone named Who has the answer. And even when I answer in a different tone of voice, with a deflection at the end, to me it's still a question. In short, even rhetorical questions end with a question mark.

Consider the same phrase in Spanish: ¿Quién sabe? – clearly a question.

Both are acceptable; however, Chicago style prefers e-mail. And E-mail at the start of a sentence. Never capitalize the "m."

Not a rule so much as understanding the meanings of the verbs "to make" and "to do," which are not at all synonymous.

The former means to create, while the latter means to perform or accomplish. If we substitute those words in your examples, we have:

create war
perform homework
create a plan
perform my business

It seems there are comparisons and superlatives for the primary colors (red, green, blue), as well as the extremes of white and black, as well as the intermediate color gray. However, I'm hard-pressed to come up with other colors for which we have such endings: purple, orange, mauve.

On the other hand, brown, browner, brownest; tan, tanner, tannest both work.

It would seem that, as is so often the case in English, there isn't a particular scheme to how colors acquire superlative or comparative endings.