Firstly, it doesn't sound like Rage to me - you have identified many triggers for his barking/aggression, which just does not fit with Rage (which is very rare).
What methods have you tried to curb the barking? What did the 2 behaviourists suggest was happening??
If you are willing to post where you are, someone might be able to suggest a behaviourist who isn't just going to give up on him if it isn't an easy fix.
From what you describe, it sounds like something spooked him, and he has generalised that event into high anxiety in your house - so any small "threat" reignites that anxiety. Honey has a lot of barrier frustration, and sounds like she is mauling something when she is let out of the back door - as you described, during the summer when the door was left open, her garden barking was greatly reduced.
We have managed to get her to respond to being called in (for a treat) the minute she starts barking in the evenings now (but it's taken quite a long time).
It does sound like he could benefit from some T-Touch, it would also be worth looking at the "Protocal for Relaxation" (should be easy to find on a google search). But really someone needs to observe all these behaviours and give you a more personalised training scheme....
