1, Yes ma'am, article directory and article submission sites are the same.
2.You are wrong with that ma'am. There are some article submission sites that can't determine if your article is original or not specially those instant approval site, mostly are in wordpress template.
3.It's important to know what Google has to say since it is the most popular search engine nowadays with its billion users. well, I don't want seeing my site being ban or waking up one day that I can't search anymore my site in search engine because of that duplicate content. Aside from that it will cause to drop the ranking of the keywords or even worst it has no more ranking at all.