The script called for Ki-Adi-Mundi to be present at the Jedi Council meeting, however his animation model was not yet prepared. The Cerean Jedi Master does appear later in Season Two.
The 'Kyber crystal' was an important element in the early drafts of Star Wars: Episode IV - A New Hope (1977), in which Jedi carrying it could use it to boost their powers. A variation on it, spelled 'Kaiburr crystal' was used in Alan Dean Foster's 1978 novel 'Splinter of the Mind's Eye'.
Holocrons were originally developed by Tom Veitch and Cam Kennedy for the comic series Dark Empire, published in 1991-1992 by Dark Horse Comics. Since that time, they've become a mainstay in expanded universe storytelling. They're often used as power-ups or trophies in Jedi-based video games from LucasArts.
The Aurebesh text seen on the neon lights outside Cad Bane's hideout translate to gibberish, but the text seen on his computer screen can be translated to 'Ropal, Bolla; Homeworld Rodia; abilities in question; threat potential minimal'.
When Obi-Wan checks the system, the Aurebesh text on the bottom right of the screen translates to 'Jedi Temple' and the text on the bottom left as well as the smaller blinking text reads 'Rooftop.'