Development Gag: In the Flashpoint-verse, the Shazam powers were given to a group of six kids, one power each, who can join forces to summon "Captain Thunder". The use of six heroes was the original concept for Captain Marvel before the writers decided to give all the powers to just one guy, and "Captain Thunder" was the original choice for his name before they found it was trademarked.
It's also the name of the Captain Ersatz of Captain Marvel that DC introduced to fight Superman before they secured the rights to the actual character.
Genius Bonus: Almost all the references to locations involve actual roads and neighbourhoods and many of the downtown buildings are very recognizable, meaning someone with enough familiarity with Toronto can actually trace the fictional action of an episode — even when it doesn't make sense.
Screwed by the Network: CBS broadcasted the show in the US but never kept seasons together, instead airing parts at a time and without pause between season. Basically, it was treated as summer filler. ION now has American rights to air the episodes after "Shockwaves," so perhaps they'll air it more evenly.
What Could Have Been: The Original Pilot Script. included a romantically involved Jules and Ed (!) and a Sam who enjoys knitting (!!!), as well as other (more minor) changes. In an interview given by the series writers, it is also revealed they spent a lot of time working on the characters' romantic lives, and that Donna was initially going to be a negative force and a danger to the team that shook the trust and foundation of the SRU: In the writers' room with Flashpoint.