Character mistake: At the end of April and the beginning of May in 2004, Luis was decoding the CDs with the Crane secrets on them. For an extended period of time, Luis left the CDs completely unattended at Hank's house. Luis told several different people that the computer was decoding the CDs and didn't need anybody there to do it. Given that Alistair is virtually omniscient in Harmony, it's ridiculous that he didn't break into Hank's apartment and take the CDs.
Character mistake: On 3/10/06, Endora sneezed and Tabitha said "Bless you." Since Tabitha is a witch, and holy water and crosses burn her skin, and she can't enter a church, and any time Edna used to mention angels it caused Tabitha's entire house to shake, it should definitely be impossible for Tabitha to say "Bless you." The little girl sneezing was probably unscripted, and "Bless you" was the natural response of actress Juliet Mills.
Character mistake: When Kay convinces Charity to switch costumes for the Halloween Dance, Kay mistakenly calls Charity "Kay."
Character mistake: On 7/30/04, a maid enters the dining room and addresses Ethan as "Mr. Crane." Ethan's last name is Winthrop, although he lives in the Crane mansion.
Answer: I don't know about good not wanting them to be together, but I know the evil side doesn't want them together because once they sleep together, then Charity's powers will multiply, and she will be a driving force against the evil darkside.