right, but once you have a failed relationship, either choice (stay together or separate) will have a negative impact. so really, the best way to salvage the kids future is to actually repair the relationship.
Yes. Children are 800-3000% more likely to be physically or sexually abused by the mother's live-in boyfriend or step-father than by their biological father, but we don't want them to have bad feels.
Good call.
If you want your kid to have successful relationships when they grow up, FFS don't let your kid grow up in an unsuccessful one.