1) Is there an up-to-date guide on installing the Eve client onto Linux? Pref one Ubuntu noob friendly?Yep, the official wiki is probably the closest to noob-friendly you could expect.Eve Wiki
2) What differences can I realistically expect?
Some graphical glitches and you will need to patch manually.
3) Is there anything like EveMon out there for Linux users that has the same functionality?
4) Is there anything like EFT out there for Linux users that has the same Functionality?
5) Is there an Eve-based Ubuntu desktop theme anyone has a link to? (that works for 11.04 obviously)
Make your own
you can edit all themes and pictures.
6) The in-game channel mentioned in the first sticky post in this thread, is it still in use?
Nobody really knows, because it takes years for someone with sticky rights to get lost in the linux forum