Question: How did the streetcar, phone booths, and vending machines end up in the digiworld?
Answer: People who built the digital world most likely had them sent there. Gennai tells the kids in the last episode that the streetcar was from San Francisco, and he asked them to take it back for him.
Question: If Angel didn't experience a "Moment of Perfect Happiness" from his night with Darla, why does he go through the same motions he went through from losing his soul before?
Answer: Due to his epiphany, Angel basically had the 'true darkness' he worked so hard to reattain ripped away from him, like his soul was after sleeping with Buffy.
Question: After just a few series Tommy's girlfriend Stacey left the show. Does anyone know why?
Answer: She left with her new boyfriend to go to a English college.
Question: Can someone PLEASE explain the ending? The whole show was pretty confusing, particularly why everything disappeared at the end, why people lost their memories, etc.
Chosen answer: The show was originally planned to have a second season, but then it was dropped because of low ratings in Japan, thus the abrupt ending leaving everything unexplained and out in the open. Still, the show was so popular on TV in the US that The Cartoon Network decided to finance the production of the second season, which is right now coming out on DVD (I think the first three volumes are already out). This should end up tying everything nicely.
Answer: We are never told as to how they got there.