Having the same issues. Changing the computer name works....for a while but then the same problem happens. On my 5th computer and iTunes library name now but having to re enter homesharing details each time is time consuming and ridiculous. The wife is not happy that it keeps breaking (blames me....).
I am also having the same problems as others with the Remote app on iPhone and iPad not working intermittently and requiring a hard reset of the iOS device and the ATV to get it working. I am also seeing problems with accessing my shared library from an iPad - when i access it the iTunes app on the iPad crashes and restarts. I think these issues are related and are all to do with the home sharing/shared library integration of iTunes 12, Yosemite and iOS 8. All this worked before I installed these and now none of these work properly.....
I have followed all the tips in the thread, many times. Am now in the process of restoring my ATV with the new 7.0.2 software, assigning everything on my network a static IP address and ensuring everything is on the 2.4 Ghz network rather than split between this and the 5Ghz, just to try and rule out any possibilities. After 2 clean installs of Yosemite, 4 clean installs of iOS 8 on iPad and iPhone and ATV restored 3 times, I have now wasted probably 20 hours of my life trying to fix something that wasn't broken before. I feel like I just bought a PC again....
Hoping for a fix soon......or I may just go and buy that PC.....