Question: How come no one believes TJ that he was the one who threw the party, not Marcus?
Answer: It's reckless and irresponsible and it's not something that he does normally. But, it is something that Marcus would do.
Question: Given his origin, was Tim Drake really Jason Todd, just given the third Robin's name?
Answer: Tim Drake's origin in the DC Animated Universe differs significantly from his origin in the comics, but it also differs greatly from Jason Todd's. This version of the character is unique to this universe, similar to many of the other supporting characters with origin stories that range from being nearly identical to the comics to being entirely different from the comics.
Answer: Scheduling problems with Hilary Shepard Turner meant that she was unable to reprise her role as Divatox from "Turbo: A Power Rangers Movie". Carol Hoyt was brought in as a replacement until the major cast change mid-season, when Hilary returned. Carol still played Dimitria, the Rangers' mentor.