Thanks again Kyle and abc. Just a quick update - I started a trial of Adobe Acrobat Pro and played around with changing the colourspace in a PDF exported from Word. After much head scratching and research, I eventually managed to change the colourspace within the 'Print Production' options.
I verified the conversion had applied to all objects by inspecting them with the Object Inspector part of Output Preview. The ColourSpace of everything had changed to 'DeviceCMYK', which I assume is correct.
Reassuringly all black text had been converted to a CMYK of [0.75,0.68,0.67,0.902], which I assume is an acceptable representation of Rich Black. Please correct me if I am wrong.
You will see the CMY colors bleeding out of that text with any minor mis-registration of the colors during the press run (high speed presses aren't perfect) so yes that is wrong. As ABC said...it needs to be CMY=0% and K = 100%.
The visual contrast between the 100% black text and the white paper is sufficient to make the text look very black. You can confirm this by looking at black text in a magazine under a loupe.
Rich black where the other process inks are included is used for larger areas since they don't benefit from the visual contrast.
rshome123. I think maybe for a one off print run you are probably looking far too deep into the technicalities of print and just blurring the lines as much as the cmyk text would be blurred! Digital presses these days can do great things. I'm a UK based printer, and I would suggest you send the files you have to a printer and get a digital proof printed to see what you get. I think you may be happy with the results as they are, or at the very least you will know how much needs doing.