What happened with the cited addresses is just cold storage, division of coins or "dumping/exiting market". Maybe I can try to find a way to see what addresses have sent money to mintpal/ exchanges.. but yeah.. not a short term project for me..
I think as you've said you should be able to pinpoint the exchanges....
the rest if the trail stops would mean...either way, cold storage address, hold, or transferring wallets hands which also should mean holding....
and yes it's a huge job.....but sometimes the results might be surprising
also it would give much more transparency to the coin and I guess it never been done yet......
so another first for the BlackCoin
also longer one waits...more difficult this become as the number of addresses increases daily