No, it was Kendall Jenner, not Kim Kardashian. I don't remember what she was like -ok enough I guess. It wasn't the same episode as Pat Monahan. Having "special guest stars" gets them promotion so I can't really blame them.
Yes, it was (a Kardashian, specifically Kim) and yes, it was (worse!) That episode also 'starred' Pat Monahan (lead singer, Train) who's performance was better than hers by leaps and bounds.