Now, we have 2 signatures
So?
Assume they can calculate the private keys for the last 5 addresses in the list and post signatures, even then they couldn't calculate the first 2 addresses.
Also, what is this suppose to mean?
2nd chars of the addresses: CWright
1C7X4UWpSa4GteWHaRBm49fMCC2SNvJQF
1W7PDetXCcAbXnN6YQyWmAdz65WZecJs5
1r7VRs5hwFNaqWSMdAGZVoQ7uQhsesRqG
1i7JYfJiXf5ARAysJaRaECLLcnrx1Gcuw
1g7nBFZkyET8TPXBoxzBYA83XPJzwDCVT
1h7djfQ2MjojsRJQdvn6jNuJZZB9oFYLm
1t7MqxnqwmwooDjKnvV9AFkiktqUvvxkq
But then ... we can be sure that whoever created that list, has the private keys of the first 2 addresses too = has all private keys