Again, the show is darker and funnier than I remember so I wouldn't say that anything about it has aged poorly. It definitely dates to the 90's but that's part of its appeal, at least for me. And I've never been able to get through a few minutes of "Married With Children" without wanting to pull an Elvis and shoot the TV, so you're definitely not gaining any credibility by mentioning your preference for that shit.
"It was always the same thing to pander to the audience: the Conners may be vulgar turds but here's somebody REALLY bad!"
I don't think the show's nearly as formulaic as you're making it sound but yes, since pretty much all of the humor surrounding Roseanne's character comes from her conflicts with others, it makes sense that the writers would want to throw some sparring partners at her beyond the immediate family.
I can't really defend Gilbert or any of the kids as actors but still love the characters, especially Darlene and DJ. Oh yeah, season 6 is also where they introduce Becky #2 (I always preferred Becky #1 but better her than one of the other 2).