True because first thoughts always can mean well and can help you potentially make a better decision.
Implied message: in order to make your wife happy, buy her a Clean Sweep Turbo Vacuum.
This is punctuated correctly.
"Marshmallows are my favorite snack" is a complete sentence unto itself.
The comma instead of a period shows that the sentence spoken is part of the whole sentence, which includes the speaker (she) and a word to describe how the speaker said it (explained).
Thomas Jefferson, having been a big fan of the Enlightenment philosopher John Locke, talks specifically about how when a government becomes tyrannical, it is within the rights of the people to replace that government.
I believe it's have but don't take my word for it :)