No
no you do not
No, it is no necessary to underline proper nouns in a regular or formative essay, unless used to exaggerate.
Don't ever use facebook in an essay!
yes
yes
yes
No.
It is not necessary to underline product names in an essay. Instead, you can simply capitalize the product name to give it emphasis.
Well the title of your essay will be the topic that you chose to write about.
Yes, you must underline books within an essay. You cannot do quotation marks, or apostrophes on both sides of the title, bold, or italicize it. You must underline a book in an essay.
If you're typing the essay out, then you italicize it and nothing else. But if you're hand-writing the essay, then you underline it. In either case, do not use quotation marks.
If you're typing an essay, you would italicize it, if you're writing an essay, you would underline it.