Agreed. It was too much. Half of the happy endings you listed should have been cut! The only thing I'd say in the show's defence is that on the other side of the scale... Kevin died, Erin died, Zabel died. Each young person's sudden death devastated the people all around them. And the resolution to Erin's murder mystery is a tragic one that means Ryan, an even younger person, is (justly) taken from his family. And everyone's dealing with very heavy stuff already, even the minor characters like Beth, Mr. Carroll, and Dawn.
The show completely fooled me. I believed the killer was John, and