I'm going to suggest something to you that will go against everything that you're feeling and thinking right now...but I promise you, it's very important that you start doing it right now, before you make any decision.
There is a lot of resentment in your posts..about moving FOR him, losing out on your own dreams/goals FOR him, etc. etc. If you want to make wise decisions in the future...you can not do that with all the resentment that you're dealing with...it will fuel a fire that will only come back and 'burn' you.
Do you have the right to feel resentful?? You bet!!! But either reconciling or divorce..resentment will only cloud the decisions and actions you make/do. You have to accept that your H has become someone you don't even like at this point. That doesn't mean you don't still love him...but you don't know him, like him or respect him . He can no more 'fix' the way you feel than you can 'fix' his problems for him. So holding resentment towards him does absolutely no good at all..it only harms you, and could cloud the decisions you may make.
Please...try to accept that what he's done, he's done. You can't go back in the past. What is important now? How much can you forgive...how much do you want to forgive? That doesn't mean you have to forgive him...you don't...but if you want peace in your own life, you will eventually have to forgive him for all the things he's done/doing.
I think you've already answered alot of questions yourself. Like the ones about how he can treat the kids and you the way he does/has. Any normal, sane, just unhappy with marriage, want a divorce type of man wouldn't let that come between himself and his children. So..you already know that this isn't just about you and the marriage, right?
So many of us here have had our WAS treat our kids just as your H is treating yours. It's nothing new, it's nothing just special in your situation. We all know too well how this works...so please feel like a full-fledged member of this club!! LOL
I also understand what you mean about things just being more peaceful and smoother if he keeps away. As much as you want the old H back, you know this man isn't the man you remember...and it just makes things easier and less hurtful if he isn't around to remind you what a jerk he's become. This is you learning to let go of the rope...which is good for your wellbeing.
As far as Mothers Day , birthdays, anniversaries, etc. Dont expect them to be like they were in years past...they won't be. Not unless/until he makes this MLC journey all the way through. I, like others here, have felt the same pain when ignored on these and other special occasions. If this is the way he likes things, then don't do anything special on his days...and certainly don't expect him to return any special favors you've extended to him. he's not capable of that either.
Right now, everything is about him..him..him..him.
Avoiding confrontation in Hs family. Oh...do I know that one well! It also had a lot to do with the poor communication styles my xh and I had. I never understood why he wouldn't give his own opinion...or thought he always agreed with me, because he never told me different ..... that is until he decided he wanted to split...then I heard about every little thing I had done/decided/said wrong ALL the way back to when we were dating in the 70s. LOL And believe me....everything will be YOUR FAULT, because...well, just because.....
I do think it would be wise to get a financial agreement in the works. This is not to be mistaken as the first step to a divorce. This is to set in place boundaries that he cannot ignore or step over. If you decide to talk to a lawyer, explain the situation to them, letting them know that you do not want to take the first step..but you do want some type of safety net, as your H has proved that he is not responsible in paying bills, helping support the kids needs, etc. Remember...he can also affect your credit rating if he ever decided to go on a spending spree to try to make himself feel better..especially if depression/alcohol is involved.
The most important thing I can say, is that if faith is important to you...to lean on it now, more than ever. To accept that you are not the one that will be able to 'fix' things, that your H needs things inside of him fixed that only God can do..and then you need to let it go...and that means the resentment and anger. It won't happen all at once, but each day it will get easier. Especially once you start looking at him in a different light...a light that lets you see that this is hugely about him, and very little to do about you or the marriage.
Don't beg, plead or give ultimatums. Pray alot, live your life for your kids and yourself...and let the legal system deal with your Hs financials if that's the route you need to take.
Women are angels. And when someone breaks our wings, we simply continue to fly...on a broomstick. We are flexible