The Red versus Blue (RvB) Easter eggs

Credit to Maka91Productions

Terminal Location Video

Timelinks:

• Terminal 1 - Mission 2 'Requiem' - Rally Point Bravo
  At the end of the level, after defeating 2 hunters, you will come to a long hall. At the end of the hall you will view this terminal in plain sight under a clear ramp that leads to the end.
• Terminal 2 - Mission 3 'Forerunner' - Rally Point Bravo
  After a few minutes, you will defeat a small group of crawlers and a promethean, and your HUD will begin to become distorted. Once this happens, the terminal should be in a relatively plain sight under the tower structure.
• Terminal 3 - Mission 4 'Infinity' - Rally Point Bravo
  After meeting up with your teammates, there will be a short cutscene and you will spawn inside a ship. Just turn around and the terminal will be directly behind you.
• Terminal 4 - Mission 5 'Reclaimer' - Rally Point Bravo
  Midway through the level, after the first main cutscene, you will end up indoors. You will have to pick up Cortana and make your way through a hallway. Instead of boarding the elevator (primary on-screen objective) take a right and the terminal should be there.
• Terminal 5 - Mission 6 'Shutdown' - Rally Point Delta
  When progressing through this mission, you will come to a section with a bunch of light bridges. At one point you will reach the end of the path and two hunters will appear. The terminal is directly before this checkpoint, but you can easily backtrack. When going from the entrance to the location of the hunters, take the last possible left and the terminal will be located behind the structure on this platform.
• Terminal 6 - Mission 7 'Composer' - Rally Point Bravo
  Once you reach the outdoor part of this level, run across the terrain to the building that says "Atrium" on the side. At the base of that sign is the Terminal. The "Atrium" sign does repeat itself on the side of the building, but this is one the closest and in the most clear sight from where you begin this section.
• Terminal 7 - Mission 8 'Midnight' - Rally Point Bravo
  Once you get to the part of the level where you are in foot, progress through the story by clearing the rooms of enemies and moving forward. Once you enter the 3rd or 4th room, you should see the terminal located behind two pillars. Walk around to the back side to access it.

In public multiplayer, based on the experience I've had so far - the first 3 seem to be Legendary difficulty and the last 2 Heroic. Every time I play I get this same structure.

The only way to select difficulty is to start a private Spartan Ops match and you can choose the difficulty, but it doesn't appear to me that you can make it public, so you either have to go it alone (Might suit some, but I don't fancy it!) or have enough available friends.

Quite a few achievements in this game are frustrating to get because the game leans you away from the goal!