Ok, so original plots are possible, which I would HOPE is the case, considering the number of B and C-list characters walking around that could use the spotlight now and then.
This week, it's Edna Krabappel. She gets fired after Bart secretly has her boozed up during school hours. Mild comedy ensues, but nothing mind-blowing. It was a decent episode and all, but I seriously can't believe they didn't acknowledge Edna's past with Skinner AT ALL, considering how much of a focus that was for the longest time.
Skinner's all-too-brief screen time makes this one good. He's quietly become one of the series's most reliable characters.
Actually, not an original plot at all. This was a retread of "Sweet Seymour Skinner's Baadasssss Song," where Bart's hijinks get Skinner fired, and Bart tries to help him turn his life around. In fact, it's a retread right down to the fact that each teacher gets their job back due to an almost entirely unrelated bit of happenstance.
I saw the original years ago, it was spooky to me at the time. But then again, I used to be afraid of the Friday the 13th movies as well. Not sure how I'd compare the two, except to say that Britt Ekland is ten times hotter than Kate Beahan as Willow.