P.,
I hope things will work out for you!
What caught my attention in your message is the note about kids making a decision of staying with you or not.
This seems to be a real problem here.
Do you really think that teenagers who are forced to do things because the law says so, is a happy situation???
What is it you can do for them to WANT TO STAY with you>???
I mean, parents and children have a 'blood-line bond' forever, but are you all FRIENDS??? does it matter to you?
I speak of my own experience, having three kids, 25, 23, and 17. Sons are adults, and live 1000 miles away, but they call me often, just to talk, and we meet every year: that time being most precious, as we have a real friendship going on, no matter the blood-line.
With my 17 years old girl, we do not have any generation-gap feeling, we are truly friends, she trusts me, and we can talk about anything in the world. (It is funny how she loves text-messaging me when she is not at home at the moment :) - new stuff, and I adjust ).
What I mean to say, P. - what do you do to gain this friendship for a lifetime? this is a WORK to accomplish, it does not happen out of a blue on its own.
As to driving, when my daughter had a better school 30 minutes of driving from home, I did it daily, twice a day, before we moved closer, for 3 years. It was all worth it, she graduates next year with good grades and tons of great friends. Sometimes, we need to sacrifice something, if we think on the big scale, and BIG, for a lifetime goals...
It is sad that your ex lives in anger, it does not help a bit, and there is probably almost nothing that you can do about it.
What you can do, is think of your children's life and interests, and how you can be of a help, and a friend to them:
they are at the age of becoming responsible for their decisions, and I see nothing wrong in them learning to do it: it's about time, really. They need guidance of course, but they will be more and more independent, every year adding to the habits of their grown-up lives: please, remember that and respect their decisions, learning how to guide them through very gently, without imposing, but helping to see the realities of life under more angles, so that they could make their decisions consciously, caringly, thoughtfully for their own good, not forgetting that harming others in not good.
I wish you all the very best, P., and hope things will not be so frustrating, but you find a common ground!