Damn, he is spitting episode plots almost 2 decades before the show aired.
I love how subtle those gags are. Another joke you could easily miss is whenever someone crosses the bridge from 'Whitesboro' into the black neighbourhood by car there will be a zoomed-out landscape shot. If you look closely you'll notice that both sides feature their own virtually identical billboard of a housewife, only with a different skin colour.
I loved that one.
I think you're confusing thematic intent for limited writing ability. The fact that the Murphy family is miserable is kind of the point of the series in some ways, not for the sake of exulting in it but rather in showing how it's the product of a combination of circumstances: Frank and Sue's frustrated youthful ambitions, Frank's difficult relationship with his father and memories of combat in Korea, and above all, the all-consuming malaise of the economic doldrums of the 1970s. The characters aren't passive victims, though. As much as they might fight and scream and hurt each other out of frustration with the circumstances they seem to be trapped in, they keep struggling to make things better in whatever way, and it's interesting to see how, as the series has progressed, the Murphy family's relationship with each other has gradually improved in a lot of ways even as their material circumstances have in some ways worsened.
It wrapped things up for the time, but I think it was a missed opportunity to have a "present day" epilogue where it shows how everyone ended up 20-40 years later. I felt as if they could have done more plot points with baby Megan. I wish Greg Throater had more than a cameo, too, but his spotlight got taken by Louis. A handful of the voice actors died, like Smokey's. I guess it's for the best Frank didn't find out he poked holes in condoms to sell.