The reason Chris Peterson's parents are always in their pajamas is because Chris Elliott's real-life father played his dad on the show. Chris Elliott says he wanted his dad to be comfortable on the set, and to not have to deal with wardrobe changes. (As told by Chris Elliott at a book signing in San Francisco CA on 15 December 2005)
In the second season, Chris moves out of his parents' garage. Bob Elliott had grown tired of the long hours of shooting and wanted to leave the series. By having Chris move out, Bob Elliott did not have to appear in as many episodes and it was arranged so that he could film all of his scenes in one week.
The series was briefly rerun on USA Network in 2000. But all of the songs including the theme song "Stand" by R.E.M. were replaced with generic music due to licensing issues. When David Mirkin saw the episodes, he demanded that they be removed. Music licensing issues are what prevented the complete series from being released on DVD until 2012.