If George and Maria were kidnapped as a young couple, then how can they be Ninten's ancestors? This either makes Ninten's grandparent an illegitimate child with extreme Parental Abandonment (I mean, come on! When your dad finally DOES come back from outer space, he won't even talk to you!) or born on Gyiyg's planet and taken back with him, which would be odd. The former would actually make some sense, as it may have started a family trend of Disappeared Dad.
I always thought that they were kidnapped after their kid was born. After all, they could have been married for a year and still be considered a "young couple".
Why does the mayor send Ninten, probably ten years old, to go find Pippi and investigate the zoo situation, instead of the police or anyone else trained to deal with such situations as those?
Because he's corrupt. He wants to take credit for the rescue (as revealed in a Freudian Slip) and if he had sent a professional, they would of course want to be honored. On the other hand, a random kid wouldn't object too much.