Just one question more: Is this true? : When replacing all cartridges r200(220) I mean epson USES VERY much ink for CLEANING print head...
Ink when you place the last cartridge the first has much lower ink level: it is spent for cleaning..
I don't know much about the other questions, but I do know about the r200 cleaning... it seemed to me that 1/2 of the ink I used was for cleaning the head and the other half went on the paper. It is a micropiezo printhead, more prone to clogging. Also... the cleaning cycle, as far as I know, operates in conjunction with a pump which operates when the pladen goes in reverse. Don't put paper towels in front of the printer during the cleaning process, they will get sucked into the printer. But assuming the pump works in all cleaning modes and sucks at the printhead while the printhead dropps ink... well it's simply not possible to clean one chamber at a given time. There is a way around this with the SSC service utility.
Also see idle's thread on the waste tank mod on the r200. It seems the r220 also has a door in the rear from where you can pull the waste tube.