Not sure if it is against the rules or not. As far as I know, no one has determined if he is a sock for an ex member, but that would obviously be bannable.
The annoying thing is that he mixes in new user type normal ignorant questions with absurdly stupid ones. So, ignoring or responding harshly to the ones that he calls his “subtle trolling” risks setting a bad precedent for how people respond to new members who legitimately have similar questions.