muppet, i take it you have changed your mind about rehoming?? not sure, dont have time to read all the threads.
Firstly, i have to say, that actually, i think that the OP isn't being irresponsible for thinking of rehoming. It might be better for the dog. So long as the dogs needs are considered and he is found a suitable home, he might pine for a few weeks but after that he will be fine.
Stanley is a fine name for a JRT i think I have a JRT called Bob - because that was all DD could say at the time. He is a livewire and i do shut him away when nervous children come round because he is over friendly and will jump up and lick. Although to be fair this happens once in a blue moon. He is laying at my feet just now - he is like a clingon - he even follows me to the toilet. However, he is left for long periods when he needs to be, he doesn't like it, but he is a dog and has to fit in with my life. On the whole, i think he is pretty happy with his lot.
With regards to the separation anxiety - might it be because you put him away in a bit of a tizz when the other kids are around? Could he somehow be taught that he has to leave visitors alone, my dog seems to be learning that himself, after an initial wash he leaves people be unless invited. He was excellent with my neice the other week i was surprised. You could try distraction with kong toys stuffed with difficult to get at food but i find they tend to get bored with them. You could try a DAP plug in, basically this is a plug in that works like an air freshener, except it gives off doggie pheremones. They are quite expensive and you have to keep them going for a few months before things settle down but they DO work. We had one for our mad rottie, it really seemed to settle him.
I do think you have had a bit of a rough ride to be honest muppet. But i do understand the other posters points of view, but i do think that it is perfectly possible to be practical and say that as your situation has changed, you don't have the best environment for the dog and rehome him. If it is the dog however that has become the problem, that is solvable, not overnight, but by training. Have you had him castrated at all? Mine is starting to look like he might need to lose his crown jewels sometime soon. Also, take heart, he is about the age of a teenager in real life, he will settle down soon. I had this with both of my rotties, they were both quite boisterous dogs, one was a rescue and had ishoos, but once they hit about 3yo they seemed to settle themselves. I am noticing this with my mums dog too. A terrier is always going to be a handful, but just easier to control maybe.
Your call, but don;t beat yourself up if you feel you need to rehome, I would avoid giving him to a rescue centre tbh, as he will have to go through being in kennels and this could be damaging if long term. Try breed rescue - your local vets should have a directory.