print A4 as A5 (double sided)?

Make a pdf and print this from Acrobat. Acrobat has an option to print multiple pages per sheet, under page scaling. I do this all the time for printing manuals and brand standard guides, so I can fit them in my binder with less pages.

For the double sided I cannot answer as every print driver has that menu in a different location. First make sure your hardware is capable of printing double sided, so you dont spend time looking for somehting your printer cannto do. If you have a fiery look for page setup >>fiery options >> double sided or possibly buried somewhere else(pends on your fiery verison/PPD) buried in your print options.