This service is clunky. It's about time for some improvements.
How have you stayed married to such an irresponsible man for twenty years? I can't believe it.
Hey, Dad. Don’t you think it’s time for mom to stop being manipulated by pointless gossip from idly chatting with the neighbors?
You add and you subtract. This brings you back to zero. There was absolutely no point in doing those actions. Completely pointless. In fact, I'd say that was downright irresponsible of you. The extra いい is there to mean "good," as in "good, you've figured out how pointless that was, now stop."
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.