Just sent you a PM about all of the above. Also, the work-flow looks simple enough, I guess just limitations on # of articles posted & niches covered would be the only real ground rules needed. You'd need to log each email as it comes in so we can boot members that break the rules.
I might also suggest that each person brings something like 5 IPs & domains to the table ... if we're going to do this, lets do it right. 20 people sharing 20 domains is much less appealing than sharing 100 domains. It also allows us to consider theming domains and articles tightly instead of just being random. Something like 10 categories (electronics, entertainment, travel, ...) and then get people to mark what category the post should go in.
Something like:
email subject: finance||How the greatest American presidents killed the bank.
email body: words, words, words ... with some links
It also allows us to get into some riskier niches (porn, pharma, ...) without compromising the entire farm.
I've got the link structure part of that covered, it's something I've had in my arsenal for quite some time and it kicks ass.
I agree though, something that does a quick scrape to randomly check for unique sentences would be best to (loosely) verify for uniqueness in the content.