In the 2007 film, Wilbur mentions how he bailed out Maybelle and her dancers. So how come he didn't plan to bail Tracy out instead of Edna making her run away? If he did, she wouldn't have had to come up with a plan to sneak past the guards to participate in the pageant!
Wilbur didn't plan to bail anyone out, because neither his wife nor his daughter was supposed to BE there. Edna had only gone down to bring Tracy home once they realized she had snuck out of the house to march against their orders. Tracy then needed to be smuggled past the police (not just into the pageant, but also from Penny's house to the record store the night before) because she hadn't been arrested at all yet & was still wanted for the ever-escalating assault charge.
Besides, she still would have had to sneak into the pageant, because there's no way Velma would have let her in even if the police weren't looking for her.
How did Tracy get out of Penny's mom's bombshelter basement hideout thing? I know she unlocked the window or something, but we don't see Tracy coming out that way. Wouldn't she have been caught by Prudy if she snuck back out?
When Penny unlocked the window, she threw the bombshelter door key to Tracy. Either Penny's mom wasn't near the door, when Tracy snuck out, or else Tracy is very stealthy (which isn't too hard to imagine, considering that she's pretty light on her feet).
In the song "Without Love" Penny sings "Seaweed, you're my black white-knight, I've found my blue-eyed soul". What is she talking about? Black white-knight is fairly obvious, but what blue-eyed soul has she found?
"Blue-eyed soul" is a term used for white people who sing in traditionally "black" genres of music such as R&B—your Adeles, Rick Astleys, and such. Blue-eyed soul isn't for Seaweed, it's for Penny—she's saying she's found her inner "blackness," as it were.
In the 1988 film, Why would Tracy get arrested for something she didn't even do in the riot at Tilted Acres? Even then, the only thing she did was spit at the woman who shattered Link's kneecaps.
In the 2007 film, why was Prudence watching the Miss Teenage Hairspray competition if she thought the music and the show was evil?
Probably out of curiosity? Most people watch shows they don't like simply out of curiosity, or they must secretly love them.