I suggest starting with the basis that any new ones are 1+2+3+4+5+6+7 = Ponzi, and send the site owners a message pointing to this thread and encourage them to provide the proof needed to ensure they don't remain marked that way, let them do the bulk of the work to prove they are legit.
I was pretty much doing that already, but I dont think its fair to label anyone as a ponzi if I havent even checked them out, or given them an opportunity to give or highlight evidence that may be public. So as of now, and with the above linked (scam, bet on it), I just ask the questions I use as criteria and give the operator a chance to reply before defaulting their score to 7/7.