Ohhhhh, PLEASE do something for Jack!!! Do it for me because I wish so much I was there to do it.
Couldn't you try the walkies thing at least once and see if he goes nutso? Maybe put him on a leash in your yard and see if he is impossible to deal with, and if it works, just add a little more distance at a time until he's less excitable? I dunno, there has to be something to do about it.
Also, I think it's pretty likely, as you mentioned, that if he wasn't bored and neglected he wouldn't be so destructive, so maybe your yard needn't be a concern...? I could probably drive there from Cali every now and then to help with poop patrol...[size=7]maybe...[/size]