A really weird episode for sure. While I enjoyed the basic premises and several jokes from both plots, each had their fair share of problems.
For the main plot, Marge was once again rather uninteresting, and felt OOC during the roller-coaster finale ("I'll never be able to tell him 'I told you so'!"), while Homer was way too much of a jerk in the latter half ("I'm perfect" etc, various women remarks). On the plus side, most of the gags worked fairly well, such as Homer's butt ("Yeah, it'll do that"), Krusty's small role, Homer using the books as a footrest, and the large tube of old gummyworms (though the second punchline with Homer eating them was overkill). At least it wasn't a marital problem story, and it did have some sparks of creativity and originality, but it felt like it could've done so much more with its woman-using-a-man-as-a-front premise than it did. And since when can a carpenter fix a roller-coaster?
As for the subplot, it's a terrific idea, and several good jokes emerged out of it (Milhouse being allergic to his own tears, the blackboard gag, the stick-on-stick climax, "Eat shrimp and die!"), but a major aspect of it did really bother me--Bart was too over-the-top. Sure, they're rivals, and the Bart/Skinner rivalry is always fun to watch, but it's far more endearing when the viewer can root for Bart and/or Skinner (like in Boy Who Knew and Sweet Seymour). In this, Bart making Skinner eat garbage and having soda cans shot out of a ball machine at his head (ouch!) were just too malicious. I'd have liked to see more gags like the chalkboard gag--eye-for-an-eye payback for Bart's years of detention, as opposed to randomly inflicting pain on Skinner.
Anyway, I was still fairly interested throughout, even with the large number of strange or over-the-top scenes (Lenny and Carl come to mind). It's yet another palatable-yet-forgettable Jean-era episode, that has a few too many major issues keeping it from greatness.
C+