Hey again Soul. It sounds like you see a lot of great reasons to stay together. I am glad.
One thing I would say is I wouldn't just dismiss is your wife's saying she wants a divorce as idle threats. One of the hardest things is being able to recognize when how things are for the other person are not the same as how we want them to be. You wife may legitimately not be happy, but she may have been trying and trying for years to make it work because of all the reasons you mention. That doesn't mean there is no hope! But don't dismiss it when she communicates something to you. Because she is communicating something.
I get the feeling you are a decent guy who is trying so hard to make this work and do what you have to. You are focused on keeping your family together, and trust me I REALLY get that.
But, the reason I asked my original question "outside of the kids, why do YOU want to stay together?" is because its really important to understand if you stayed together and nothing changed, would you be happy? If you were being really really honest with yourself.
And the answer to that question is so important. Because if the answer is no, then that's where you need to look. What do YOU need to do for/with/to yourself to be happy? It has to be about you, not her.
I don't mean you should divorce. I don't mean you should be selfish (well I do a little). I mean if you aren't ok with you, then its much harder for you as a couple.
Keep talking Soul!