In Lr 4.2 I can tell the printer to manage color, or set the profile to sRGB. I've come across two answers, some say tell the printer to manage color, the other, is set the profile to sRGB.
Set it to 'printer manages color'. Why would you imagine setting it to sRGB? What if the orginal is in ProPhotoRGB or AdobeRGB?
The other question is what rendering intent to use when printing with ABW from Lr 4.2
The rendering intent primarily deals with mapping colors from the input space to the output space, and your output space is black and white. Anyhow, if you are in ABW, where would you be able to select a rendering intent?