Exporting PDF's Printing, Lineweights and Colours etc.

[BLM]

When exporting a PDF some colours do not 'print' and lineweights default to a single weight. Why? Also, is there a way of saving the exported PDF as a B&W image when exporting??

I am able to save in this way printing a sheet layer as a PDF for an attached printer, ie in B and W, but not in a format for which a printer is not available. Is it possible to choose a Printable Area paper format,eg. A1 in Page Setup, select for any printer in Printer Setup and not get the vertical and horizontal page numbers defaulting to a proportion od the default printer setup??

Confused. The Cute PDF writer in Windows was a lot more straightforward printing what was on the screen to a desired format. Perhaps someone can demystify this for me.