In room 1: TV + Apple TV with aTV Flash
In room 2: Good spec Apple Mac and 2Tb external hard drive
both on a wireless network.
In room 3, I have bookshelves with 1000 DVDs that I’d rather use to house books.
Using this set up:
Could I transfer the DVDs to the 2Tb drive?
What extra s/w etc would I need to do this?
Could I play the DVDs over the wireless network via ATV without crashes/pauses?
If not, how would they need to be connected?
Could I create a menu on the Mac that is accessible via the TV with a remote?
Yup, just rip them to preferably ISOs using AnyDVD/DVDShrink on your Win-PC, or Mac The Ripper or similar on OS X, or DVD95 (sudo apt-get install dvd95) on Ubuntu/Linux.
If space become an issue, you can always use Handbrake (available on Win, Mac and Linux) or similar to re-encode them to a different format.
See previous question.
DVDs should work over a G-network with excellent signal, but you need to try to be sure, if you re-encode them to H264 or similar, they should work just fine to stream on a G-network as long as you have a decent signal.
Via a switch to your Router, or use the built in switch on the router. Use CAT5e or better cables.
Not sure what you are asking, but if you have a DLNA compliant TV (most newer Samsung TVs with ethernet are), you should be able to set up a DLNA server on the Mac (http://snipurl.com/vyad8), and access the media via the TV remote.
Alternatively (my choice) is to set up a samba (smb/CIFS) share on the Mac, and have XBMC installed on the Apple TV and just access the share through that. This can be done with nitoTV and Sapphire on the Apple TV also, but I prefer XBMC…