Executive Meddling: As noted in the description, after Gravity was nearly destroyed by a hacking incident at the end of the first closed beta, Samsung 'saved' them by buying them out. Samsung then put a director in place to oversee the recovery of the almost totally destroyed game, who tried to impose his radically different vision on the design team. Samsung caught wind of this when a very large portion of the design team proceeded to rebel and quit, however, and pulled the director, installing someone else with instructions to leave the development be, and while some damage was done, disaster was largely averted.
Homage / Shout-Out: The advance job class of the Gunslinger is called Rebellion. Many Westerners seem confused as to why it isn't called Rebel. The movie Equilibrium is known as Rebellion in Japan and Korea (because the original Equilibrium title doesn't translate well into Japanese or Korean). The film has a major pop culture following in those two countries, and the Gun Kata inspired Gunslinger is just one of many examples found in manga, anime, manwha, and video games. The advanced job class is directly named after the movie.
What Could Have Been: While the hacking incident that almost killed all of gravity's plans for RO is famous there are some lesser known things that could had been.
There was a USA-themed town/city and dungeon planned at one point. A BGM called "Antique Cowboy" seems to be all that is left of this.
The Creator/Biochemist was originally supposed to have the animated shoulder pads that the Geneticist has in their idle battle stance, but players liked the look of the non-animated pads enough to keep them.
The Wiki Rule: Various licensed and private servers have their own, but there are a few out there that cover the game regardless of server.
The iRO Wiki, which has its own database. While only applicable to iRO, it's probably the biggest and most detailed wiki to date.