Well, I think that being bi-polar should be a disqualification for gun ownership. I know two people who are bi-polar.
Yes, when on medication, they are fine. However, they get all out of sorts if they go off of the meds. Will they shoot someone? Probably not, but it is a severe disorder where they put themselves in great danger if they go off their medication.
Divorce on the other hand, is not a disqualifier. Let's be realistic here, who doesn't know a couple that had a vicious divorce proceedings? I know enough people who hate their exes with so much rage that they would make them miserable as possible many years after the divorce is over.
The only time personal relationships can come into play, is if there is documented domestic abuse. That comes about from criminal proceedings, and not talking to any ex.
I'd take the gun ownership laws in my home state over those in Canada any day of the week. Wisconsin is even behind the times when it comes to self defense laws, and we still don't have a CC law. I'm waiting to see what changes are brought about by the now conservatively led houses and Governor.