Beam Me Up, Scotty!: Contrary to popular criticisms, a few Barney fans debunked the rumor that Barney described strangers as being "friends you never met." Instead, the very opposite was stated by Derek in the episode Playing It Safe (he said that they're not only people you don't know, but that "they could be bad people."), which led to a short Too Smart for Strangers moral using a play of Little Red Riding Hood and a song (in traditional Barney fashion) to reinforce the moral of not talking to them.
Dawson Casting: Some of the kids are well into their preteen years by the time they leave the show. Chip was a notable case. Luci looked a lot older than the other kids.
Of course, Luci was Tina's older sister, so it was semi-justified.
The Barney suit was originally going to be somewhat more "realistic" looking, with scales, claws, pointed teeth, and even lacrimal ridges. Through the various drafts, the creative team kept telling costume designer Irene Corey that the costume would be too frightening for kids, until it came to what would become Barney's eventual design. Proof: