Speaking of Chance, things have been getting better. We followed everyone's advice and got a crate for him, but after he injured his foot and rubbed his nose bloody and raw on the bars, then somehow busted down the front of the crate, we figured it just wasn't going to work for us.
So we cleared out the guest room. There wasn't much in there anyway, but we took out everything he could potentially destroy or hurt himself on -- the mattress, box spring and bedding, and the television -- and raised the blinds so he can't reach them and so he can look out the windows. We put his bed and some toys in there, and we gave him a few things that smelled like us so he could rip them apart. He still has separation anxiety and he barks when we leave and he's kind of slobbery when we get home, but it feels like a better solution for him than putting him in a crate. We just don't have a guest room for a while, I guess, until he gets used to the idea that we're not abandoning him.
Also he's stopped the mounting thing, I think. He hasn't done it in a while, anyway. I got tough on him once, pushed him down and told him no really loudly, and I think he got the message.
We all went camping the other weekend and he was the perfect dog. He behaved himself well in the campsite and on the trails; we didn't even have to have him on the leash because he stayed with us the whole time (he spent the time on the trails constantly checking to make sure we were all there and no one had fallen behind). He's a great outdoor dog.