If you come across as criticising him and ex-wife parenting skills, it could be a deal breaker. You do come across that way - and I don't mean that negatively.

On the other hand he just might be willing to see that the habits he and ex-wife built up over the years are only habits, and that his relationship with you is worth more than that.

I think a lot depends upon his attitude to his relationship with you and his ability to work at adapting to being with you. He does seem set in his ways, and his parenting is only one part of that.

If he's not willing to work on his relationship with you, and to give that equal value, then>>>