I tried as well changing the printing mode in the printer properties - not spooling the data but sending them directly to the printer , I had the impression that this improved the performance but only for a few days for some unkown reasons, and then the same problems came back. Since I'm using only Epson printers and a Brother MFC I don't know whether WLAN connected Canon printers would show the problems.
And I tried another setup for a while - I'm using USB print servers to connect several printers to some computers via LAN, these print servers emulate USB via LAN, and you can print from several computers to several connected USB connected printers. This works (almost) flawlessly via LAN, there are a few hiccups releasing and connecting a printer from one computer to another. I uses a WLAN print server as well for a while which was working, I did not get intermittant stops and breaks of print jobs, but printing overall was pretty slow, the printer was printing a few lines - waiting for data and then printing a few lines again, but it did even 2GB spool files for posters on a Pro 7600, the transmission via (W)LAN is invisible to the user, he just sees the printers connected locally to virtual USB ports. Scanning works as well via such print server connection, even connection to an USB drive stick. I can print as well from a WLAN connected notebook to the available printers, the printers appear as locally connecte USB devices, the transmission via TCP/IP is done by the print server software you need to install on every computer