Caution: theory mafia ahead
Keep in mind, there are two vote-changers, one good guy and one bad guy, so a vote may not mean much unless it's stacked by two votes or more. This favors the bad guys substantially since they know who they are, but the good guy (psychologist) still has to guess.
So think about what happens in a close vote - the bad guys will change the vote away from themselves, or arbitrarily change it if both top contenders for a vote are good guys. What happens the next turn is that whoever almost got voted out will probably get voted out, and that will be whoever was up for vote just before. Both scenarios are worse than having a strong margin of votes in the first vote.
For the psycholigst, arbitrary vote changing without intel or statistical probability is a bad move, as it makes it more ambiguous as to who is changing votes and why; it obscures the mafia's actions. Wait until it's actually probable that you're changing a vote to a bad guy.
I think the smart thing to do would be for the librarian, if I understand their role correclty, is to use all 3 of the investigations they get immediately, identify themselves in PMs with the good guys they find, and start a solid voting group.
Also, in the interests of substantial numbers of votes, I'll vote this because I like thatguy's brazen immediate vote, I don't think the bad guys would do it. But my door is open if some guys want to get together for a voting bloc.
vote Mop it up