Hello FRLAoffice,
Welcome to the HP Support Forums!
I think I can help answer your question regarding printing black only with the Officejet 4500 on Mac OS X. When you have the cable connected it uses a different driver and presets, this would explain why when you connect wireless you do not have the options.
This HP document: Mac OS X: Printing with the Black Print Cartridge Only Option will walk you through creating a black only preset to select for the wireless connection.
I hope this has helped,