Also I read today that John has been caught turning the mining off and on, thus the test net is not a unprotected P2P network where the adversary can apply all his potential powers.
That was the live network, people agreed on it, it was needed for testing purposes. TestNet is untouched since deployed. Either read over stuff properly or don't comment on them at all.
All we asked was for him to explain how he would handle Sybil and DoS attacks
You would probably know by now that John isn't here to answer the question. Jump on IRC (#vanillacoin) or send him a message through BM.
I have no obligation. He can come here where I talk to clear the matter or not. Ball is in his court.
John has been caught doing several questionable actions, thus I don't know what he is doing with the testnet. What ever is written is irrelevant, since he has already been caught lying (or exaggerating) about not copying Bitcoin source code.