1. If the defamatory words were neither written by me nor originate from me, and I have simply repeated the publication to others, will I be liable for defamation?
If one person speaks to another person once, this counts as one publication. When the latter repeats the same thing to yet another person, it is a second publication. The second publication is a fresh instance of defamation (if the content is defamatory).
Merely quoting other people's words is regarded in law as publication. If the words are defamatory, the one who merely repeated those words is liable for defamation. No matter how many times the words are repeated, each repetition is one instance of defamation.