This is really very good.  Your story has sort of a British Farce bent to it, as well as lapoooning the characters a little bit and keeping up with the themes of the show as a whole.
  
  The religious fanatic at the begining could be a truly frightening villain if inserted into a more thriller/horror type of story, I like him a lot so far.  It has also got me thinking that Caleb could have been a phenominal villain if treated differently. (Small digression there.)

  Cool story so far, Wrathful Buffy was remarkably entertaining.

Text    I couldn't leave a review for the last chapter because the words to type disappeared. I did something, but I don't know what. This is agood story; I really like it. But another person's gluttony really isn't exciting

Poor Tara!  Loved the part with the cookies, so cute!

You are really fleshing out the consequences of these sins rather nicely.   Poor Tara, this is so unlike her.   When will the weight gain show?  However, Willow is just ramped up Willow.

now I've got the munchies - so good work on the description of Tara's affliction, and Willow really can convince herself that what she is doing is all for the good.