Thanks for the additional information and photos. I appreciate that you pay close attention to detail and carefully follow instructions. Please understand, I work with a wide range of people using our products, so need to be thorough with the questions I ask and information I gather to trouble shoot issues via email, since I'm not at the customer's printer and don't know everything that's been done (and believe me, I have heard of and seen all sorts of crazy things being done).
As I said earlier, the video showing the initial fill of cartridges being done via vacuum method, and refilling done by injection was specific to the older cartridge design, and does NOT apply to the new model carts. The current cartridge design does not need to be vacuum filled, and can be injection filled/refilled.
Yes, distilled water, and if you want a weak alcohol solution is good for cleaning. We recommend not using ammonia or strong alcohol on the print head, because fast drying is bad for the print head.
The nozzle check you posted only shows 4 of the 8 channels. From that nozzle check, it looks like the LLK channel was consistently printing good, and the LM, LC and LK look like they got better, but then experienced some flooding from the capping station after doing too many cleaning cycles. On page 37 of the Epson R2880 User's Guide (under the Checking and Cleaning the print Head section), it does say "If you don't see any improvement after cleaning the print head four times, turn off your printer and wait at least six hours", and "If you don't use your R2880 often, it is a good idea to print a few pages at least once a month to maintain good print quality".
Yes, if it takes you a long time to type your post, you may get timed out. I've had this happen to me a few times (very annoying), because I typically have several tabs open at once, and am working with several customers at the same time, so I now make sure to copy what I typed before pushing "post", so if I get timed out, I can just paste and not have to retype everything again...
Please keep me posted, and let me know if you have further questions or there's anything else I can help you with.
Best regards~ Dana