Welcome from Huntsville, AL, Tannis!
To answer three of your questions:
2. Yes, kinda? Hard to say, but occasional humor is allowed, as long as it doesn't go too far, from my observation.
4. Just use the quote brackets, and copy-paste the text from the website you want to quote between them like so:
[quote="website"]
Pasted text.
[/quote]
or
[quote]
Pasted text.
[/quote]
And I'd personally recommend putting a link to the website you got the text from to make it easier to reference, either above or below the quoted text.
5. I'd say go ahead, especially if you have new and/or relevant info to add to the thread.