Question: Topanga said in one episode that she has a weird middle name, did she ever say what it is?
Question: In early episodes, why did Topanga call her parents by their first names?
Answer: That was what I hope was only a phase of the way things were in California at that time. Many kids who had parents who liked to be modern and be friends more than parents to their kids had them call them by their first names.
I've watched episodes of "Alfred Hitchcock Presents," made in the 1950s-60s, where some characters sometimes referred to parents by first names. Although, the characters were adults, so maybe it was acceptable for full-grown children? I guess it just depends on the specific relationship and what a parent wants to be called.
Question: Why did they switch out the actor of Morgan?
Answer: Per thelist.com: Lily Nicksay told Entertainment Weekly her leaving the show "was a mutual decision between her parents and the producers." At Wizard World Comic Con, Rider Strong provided more insight into the situation by stating Nicksay "was not very happy... At that time, she was a little girl who did not want to be on the show." She was four years old when she filmed the pilot and most likely six years old when they filmed season 2.
Answer: Topanga's middle name is never specified. Considering her sister's name is Nebula Stop-the-war Lawrence, Topanga's is probably something equally unusual.