It is a Canon trademark. From http://en.wikipedia.org/wiki/Bubble_Jet :
To produce an image, the printer runs a pulse of current through the heating elements causing a steam explosion in the chamber to form a bubble, which propels a droplet of ink onto the paper
I too have an Epson photo printer. If it gives you a message to service and you go online and that has failed, have you called their 1-800 number? If not then try that. Also, they should have a website you can go to and find help and maybe even a phone # so you can talk to a real person and not a recording. One more thing, if you live near Best Buy, they have what they call a "Geek Squad" and they can come out to your home and fix your printer for you.
There are no steps. You just open the printer, pull out the empty toner cartridge, replace it with a new toner cartridge, and then close the printer once again. It's a very simple process, typically no harder than replacing an ink cartridge for an inkjet printer. The only difference is that toner cartridges tend to be larger and provide more pages of print per cartridge than their inkjet cousins.
Yes, you can connect one printer to each computer and connect both computers on a local network, then install the network printer from each other's computer.
Or you can give printer servers to two different printers.