After Darlene and David start dating, an episode deals with him being overly clingy and constantly hanging around the Connor house. All aimable and typical, right? Well, not too many episodes later, viewers meet David's abusive mother and get a good idea of what his home life is like. Re-watching the earlier episode with that in mind, David has more of a reason to cling to Darlene than what everyone else thought. It also explains why he latched so hard to Darlene of all people. There's the old saying about how people seek out people who act like their parents. His relationship with his mother is physically abusive at worst, but emotionally abusive even at the best of times. He clung to tightly to Darlene because she acts a lot like his mother does and that's merely what he's used to. Their relationship is a Freudian field day.
The Conners struggle financially, but live in a three-bedroom house with private bathrooms for each, with a garage, laundry room, and a finished basement. Most of the improvements were probably Dan's handiwork.
Jackie's Flanderization from a clever, confident and slightly neurotic woman to a complete basket case. Her father's abuse of her and Roseanne was bad enough, but then her boyfriend Fisher started to hit her. The one-two punch of an abusive father and boyfriend plus all the other bad luck she had in romance and careers left her a broken woman.
David becoming more of a snobbish Jerk Ass in the later seasons. A crappy home life, being an Extreme Doormat to his controlling and sarcastic girlfriend, bullied by not only his older brother but said girlfriend's younger brother and then being dumped? Eventually a person's gonna get fed up and start pushing back, and this was the only way someone like David could.
Early in the series it was established Lanford was in Fulton County, Illinois, in the West Central part of the state. Other episodes place in closer to Chicago though. Considering the series is a book written by Roseanne this goof can be handwaved. She took creative liberties while writing the story.
Roseanne and Dan's respective arguments with God after Dan's heart attacks take on a different meaning after the finale. Dan actually died of his heart attack. His begging for God to let him live is the begging Roseanne herself must have done while he was in the emergency room, and Roseanne's accepting responsibility for cooking all the unhealthy meals that clogged his arteries must have come later in her grieving. Both conversations were from her point of view at different times in her grief.
Michael Des Barres as the doctor who treats baby Harris. He also played Leon's (very well-dressed) partner in season 4, so why not imagine him as a brilliant doctor?