The OP won't be back. She came, hoping for sympathy and validation - she had already decided how she was going to proceed as evidence by her latest post - she has already attempted to start the process of changing the kids' names to her's and doesn't want the ex or his wife to have a role in their lives.
Everyone handwringing about her "feelings" has missed the fact that the OP is literally using her "feelings" to deny the children their relationship with their father because she is jealous and bitter that he has settled down, gotten married, and is different in his current relationship than he was in theirs.
From the way she talks about him, the ex wasn't happy or ready to be in a relationship with the OP. According to her, he told her he would never marry her, didn't want kids, was never home - despite this, the OP went on to have more than one child with him, and now seems surprised that he has left her. Just because she wasn't the relationship for him, doesn't mean that he doesn't love his kids, and that he can't have changed and settled into a relationship with his wife, whom it would appear he is happy with.
The OP sounds nasty and manipulative, and if she is how she comes across, it's really no surprise that the ex wants his wife with him whenever he has to be in the same place as her, and is refusing to bow down to her demands. I just hope he's strong enough to seek legal representation and not allow the OP to destroy his relationship with his children, and yes, possibly go for a higher percentage of custody. It might stop his children being brainwashed and manipulated any further, or at least lessen it.