I don't think anybody should be friends with an abusive ex. But you can do what you want i personally wouldn't but it's up to you.
Depends who ur abusive ex is
I am sure that it would depend on the abusive ex-husband.
Do nothing.No more contact with that "good" friend, either.
if he is that abusive chances are he will but then only if you tolerate him.
No you shouldnt.
SOME PEOPLE TODAY HELP THERE ABUSIVE EX'S BECAUSE THERE IN NEED OF CHAGING THERE LIFE'S AND BECOMING THE BETTER PERSON THEY ALSO NEED THE ABUSIVE PERSON TO CONSIDER THAT THERE IS A SECOND WAY FOR THEM TO ACT DURING THE CHARGING PROCESS.
It's not ever really safe to assume an abusive man wont bother you. They're abusive, that's what they do. The only reason they would stop abusing you is if there were no longer a pay off, or they found someone new to abuse.
Get a restraining order.
If he can put the past aside there is a chance, but that takes time.
Keep them away from the father and make an agreement with him not to be verbally abusive to your children
This is what you do. Get a voice recorder and record it than show it so people believe you
Why does it matter? He's your ex.