Can I use these interchangeably?
It's good that you brought it up. /  I'm glad that you brought it up.

 Never come between a husband and wife. /  Never interfere between a husband and wife

 I have a happy marriage.  /  I am happily married.

The second and third pairs are 100% interchangeable.

The first often will be, but not always: there are sometimes good things that don't make us happy.