Perhaps he has a thing for mentally ill women but is smart enough not to stick his dick in crazy? It does appear to me that he is finding this whole situation entertaining.
You can't be sure that they are actually murderers. The rabbit is either of supernatural origin or this is all some kind of computer simulation from an advanced civilisation. Either way all the memories Es is seeing could be faked.
People go to school so they can get a certificate in the end which they need to find employment or enter university. Without certifications you are fucked in any first or second world country.